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Recent Mozilla Thunderbird Security Advisories

Advisory Title Published
mfsa2021-47 Security Vulnerabilities fixed in Thunderbird 91.2 mfsa2021-47 October 6, 2021
mfsa2021-46 Security Vulnerabilities fixed in Thunderbird 78.15 mfsa2021-46 October 5, 2021
mfsa2021-41 Security Vulnerabilities fixed in Thunderbird 91.1 mfsa2021-41 September 7, 2021
mfsa2021-42 Security Vulnerabilities fixed in Thunderbird 78.14 mfsa2021-42 September 7, 2021
mfsa2021-37 Security Vulnerabilities fixed in Firefox 91.0.1 and Thunderbird 91.0.1 mfsa2021-37 August 16, 2021
mfsa2021-36 Security Vulnerabilities fixed in Thunderbird 91 mfsa2021-36 August 11, 2021
mfsa2021-35 Security Vulnerabilities fixed in Thunderbird 78.13 mfsa2021-35 August 10, 2021
mfsa2021-30 Security Vulnerabilities fixed in Thunderbird 78.12 mfsa2021-30 July 13, 2021
mfsa2021-26 Security Vulnerabilities fixed in Thunderbird 78.11 mfsa2021-26 June 3, 2021
mfsa2021-22 Security Vulnerabilities fixed in Thunderbird 78.10.2 mfsa2021-22 May 17, 2021

By the Year

In 2021 there have been 44 vulnerabilities in Mozilla Thunderbird with an average score of 7.3 out of ten. Last year Thunderbird had 76 security vulnerabilities published. Right now, Thunderbird is on track to have less security vulnerabilities in 2021 than it did last year. Last year, the average CVE base score was greater by 0.27

Year Vulnerabilities Average Score
2021 44 7.33
2020 76 7.61
2019 57 8.42
2018 49 8.26

It may take a day or so for new Thunderbird vulnerabilities to show up in the stats or in the list of recent security vulnerabilties. Additionally vulnerabilities may be tagged under a different product or component name.

Recent Mozilla Thunderbird Security Vulnerabilities

Uninitialized memory in a

CVE-2021-29980 8.8 - High - August 17, 2021

Uninitialized memory in a canvas object could have caused an incorrect free() leading to memory corruption and a potentially exploitable crash. This vulnerability affects Thunderbird < 78.13, Thunderbird < 91, Firefox ESR < 78.13, and Firefox < 91.

Missing Initialization of Resource

Firefox incorrectly treated an inline list-item element as a block element

CVE-2021-29988 8.8 - High - August 17, 2021

Firefox incorrectly treated an inline list-item element as a block element, resulting in an out of bounds read or memory corruption, and a potentially exploitable crash. This vulnerability affects Thunderbird < 78.13, Thunderbird < 91, Firefox ESR < 78.13, and Firefox < 91.

Interpretation Conflict

A use-after-free vulnerability in media channels could have led to memory corruption and a potentially exploitable crash

CVE-2021-29985 8.8 - High - August 17, 2021

A use-after-free vulnerability in media channels could have led to memory corruption and a potentially exploitable crash. This vulnerability affects Thunderbird < 78.13, Thunderbird < 91, Firefox ESR < 78.13, and Firefox < 91.

Dangling pointer

Instruction reordering resulted in a sequence of instructions

CVE-2021-29984 8.8 - High - August 17, 2021

Instruction reordering resulted in a sequence of instructions that would cause an object to be incorrectly considered during garbage collection. This led to memory corruption and a potentially exploitable crash. This vulnerability affects Thunderbird < 78.13, Thunderbird < 91, Firefox ESR < 78.13, and Firefox < 91.

Due to incorrect JIT optimization, we incorrectly interpreted data

CVE-2021-29982 6.5 - Medium - August 17, 2021

Due to incorrect JIT optimization, we incorrectly interpreted data from the wrong type of object, resulting in the potential leak of a single bit of memory. This vulnerability affects Firefox < 91 and Thunderbird < 91.

Missing Release of Resource after Effective Lifetime

An issue present in lowering/register allocation could have led to obscure but deterministic register confusion failures in JITted code

CVE-2021-29981 8.8 - High - August 17, 2021

An issue present in lowering/register allocation could have led to obscure but deterministic register confusion failures in JITted code that would lead to a potentially exploitable crash. This vulnerability affects Firefox < 91 and Thunderbird < 91.

Mozilla developers reported memory safety bugs present in Firefox 90 and Firefox ESR 78.12

CVE-2021-29989 8.8 - High - August 17, 2021

Mozilla developers reported memory safety bugs present in Firefox 90 and Firefox ESR 78.12. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Thunderbird < 78.13, Firefox ESR < 78.13, and Firefox < 91.

Buffer Overflow

Mozilla developers reported memory safety bugs present in code shared between Firefox and Thunderbird

CVE-2021-29976 8.8 - High - August 05, 2021

Mozilla developers reported memory safety bugs present in code shared between Firefox and Thunderbird. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Thunderbird < 78.12, Firefox ESR < 78.12, and Firefox < 90.

Memory Corruption

A malicious webpage could have triggered a use-after-free, memory corruption, and a potentially exploitable crash

CVE-2021-29970 8.8 - High - August 05, 2021

A malicious webpage could have triggered a use-after-free, memory corruption, and a potentially exploitable crash. *This bug could only be triggered when accessibility was enabled.*. This vulnerability affects Thunderbird < 78.12, Firefox ESR < 78.12, and Firefox < 90.

Dangling pointer

If Thunderbird was configured to use STARTTLS for an IMAP connection

CVE-2021-29969 5.9 - Medium - August 05, 2021

If Thunderbird was configured to use STARTTLS for an IMAP connection, and an attacker injected IMAP server responses prior to the completion of the STARTTLS handshake, then Thunderbird didn't ignore the injected data. This could have resulted in Thunderbird showing incorrect information, for example the attacker could have tricked Thunderbird to show folders that didn't exist on the IMAP server. This vulnerability affects Thunderbird < 78.12.

Files or Directories Accessible to External Parties

Mozilla developers reported memory safety bugs present in Firefox 88 and Firefox ESR 78.11

CVE-2021-29967 8.8 - High - June 24, 2021

Mozilla developers reported memory safety bugs present in Firefox 88 and Firefox ESR 78.11. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Thunderbird < 78.11, Firefox < 89, and Firefox ESR < 78.11.

Buffer Overflow

Thunderbird unprotects a secret OpenPGP key prior to using it for a decryption, signing or key import task

CVE-2021-29950 7.5 - High - June 24, 2021

Thunderbird unprotects a secret OpenPGP key prior to using it for a decryption, signing or key import task. If the task runs into a failure, the secret key may remain in memory in its unprotected state. This vulnerability affects Thunderbird < 78.8.1.

Cleartext Storage of Sensitive Information

Ports that were written as an integer overflow above the bounds of a 16-bit integer could have bypassed port blocking restrictions when used in the Alt-Svc header

CVE-2021-29946 8.8 - High - June 24, 2021

Ports that were written as an integer overflow above the bounds of a 16-bit integer could have bypassed port blocking restrictions when used in the Alt-Svc header. This vulnerability affects Firefox ESR < 78.10, Thunderbird < 78.10, and Firefox < 88.

Integer Overflow or Wraparound

If a MIME encoded email contains an OpenPGP inline signed or encrypted message part, but also contains an additional unprotected part, Thunderbird did not indicate

CVE-2021-29957 4.3 - Medium - June 24, 2021

If a MIME encoded email contains an OpenPGP inline signed or encrypted message part, but also contains an additional unprotected part, Thunderbird did not indicate that only parts of the message are protected. This vulnerability affects Thunderbird < 78.10.2.

When loading the shared library

CVE-2021-29949 7.8 - High - June 24, 2021

When loading the shared library that provides the OTR protocol implementation, Thunderbird will initially attempt to open it using a filename that isn't distributed by Thunderbird. If a computer has already been infected with a malicious library of the alternative filename, and the malicious library has been copied to a directory that is contained in the search path for executable libraries, then Thunderbird will load the incorrect library. This vulnerability affects Thunderbird < 78.9.1.

DLL preloading

Signatures are written to disk before and read during verification

CVE-2021-29948 2.5 - Low - June 24, 2021

Signatures are written to disk before and read during verification, which might be subject to a race condition when a malicious local process or user is replacing the file. This vulnerability affects Thunderbird < 78.10.

Race Condition

The WebAssembly JIT could miscalculate the size of a return type, which could lead to a null read and result in a crash

CVE-2021-29945 6.5 - Medium - June 24, 2021

The WebAssembly JIT could miscalculate the size of a return type, which could lead to a null read and result in a crash. *Note: This issue only affected x86-32 platforms. Other platforms are unaffected.*. This vulnerability affects Firefox ESR < 78.10, Thunderbird < 78.10, and Firefox < 88.

Incorrect Calculation

OpenPGP secret keys

CVE-2021-29956 4.3 - Medium - June 24, 2021

OpenPGP secret keys that were imported using Thunderbird version 78.8.1 up to version 78.10.1 were stored unencrypted on the user's local disk. The master password protection was inactive for those keys. Version 78.10.2 will restore the protection mechanism for newly imported keys, and will automatically protect keys that had been imported using affected Thunderbird versions. This vulnerability affects Thunderbird < 78.10.2.

Cleartext Storage of Sensitive Information

When a user clicked on an FTP URL containing encoded newline characters (%0A and %0D), the newlines would have been interpreted as such and

CVE-2021-24002 8.8 - High - June 24, 2021

When a user clicked on an FTP URL containing encoded newline characters (%0A and %0D), the newlines would have been interpreted as such and allowed arbitrary commands to be sent to the FTP server. This vulnerability affects Firefox ESR < 78.10, Thunderbird < 78.10, and Firefox < 88.

Argument Injection

If a Blob URL was loaded through some unusual user interaction, it could have been loaded by the System Principal and granted additional privileges

CVE-2021-23999 8.8 - High - June 24, 2021

If a Blob URL was loaded through some unusual user interaction, it could have been loaded by the System Principal and granted additional privileges that should not be granted to web content. This vulnerability affects Firefox ESR < 78.10, Thunderbird < 78.10, and Firefox < 88.

Improper Privilege Management

Through complicated navigations with new windows, an HTTP page could have inherited a secure lock icon from an HTTPS page

CVE-2021-23998 6.5 - Medium - June 24, 2021

Through complicated navigations with new windows, an HTTP page could have inherited a secure lock icon from an HTTPS page. This vulnerability affects Firefox ESR < 78.10, Thunderbird < 78.10, and Firefox < 88.

Insufficient Verification of Data Authenticity

When Responsive Design Mode was enabled, it used references to objects that were previously freed

CVE-2021-23995 8.8 - High - June 24, 2021

When Responsive Design Mode was enabled, it used references to objects that were previously freed. We presume that with enough effort this could have been exploited to run arbitrary code. This vulnerability affects Firefox ESR < 78.10, Thunderbird < 78.10, and Firefox < 88.

Operation on a Resource after Expiration or Release

A WebGL framebuffer was not initialized early enough, resulting in memory corruption and an out of bound write

CVE-2021-23994 8.8 - High - June 24, 2021

A WebGL framebuffer was not initialized early enough, resulting in memory corruption and an out of bound write. This vulnerability affects Firefox ESR < 78.10, Thunderbird < 78.10, and Firefox < 88.

Missing Initialization of Resource

An attacker may perform a DoS attack to prevent a user from sending encrypted email to a correspondent

CVE-2021-23993 6.5 - Medium - June 24, 2021

An attacker may perform a DoS attack to prevent a user from sending encrypted email to a correspondent. If an attacker creates a crafted OpenPGP key with a subkey that has an invalid self signature, and the Thunderbird user imports the crafted key, then Thunderbird may try to use the invalid subkey, but the RNP library rejects it from being used, causing encryption to fail. This vulnerability affects Thunderbird < 78.9.1.

Use of a Broken or Risky Cryptographic Algorithm

Thunderbird did not check if the user ID associated with an OpenPGP key has a valid self signature

CVE-2021-23992 4.3 - Medium - June 24, 2021

Thunderbird did not check if the user ID associated with an OpenPGP key has a valid self signature. An attacker may create a crafted version of an OpenPGP key, by either replacing the original user ID, or by adding another user ID. If Thunderbird imports and accepts the crafted key, the Thunderbird user may falsely conclude that the false user ID belongs to the correspondent. This vulnerability affects Thunderbird < 78.9.1.

Improper Verification of Cryptographic Signature

If a Thunderbird user has previously imported Alice's OpenPGP key

CVE-2021-23991 6.8 - Medium - June 24, 2021

If a Thunderbird user has previously imported Alice's OpenPGP key, and Alice has extended the validity period of her key, but Alice's updated key has not yet been imported, an attacker may send an email containing a crafted version of Alice's key with an invalid subkey, Thunderbird might subsequently attempt to use the invalid subkey, and will fail to send encrypted email to Alice. This vulnerability affects Thunderbird < 78.9.1.

A texture upload of a Pixel Buffer Object could have confused the WebGL code to skip binding the buffer used to unpack it

CVE-2021-23981 8.1 - High - March 31, 2021

A texture upload of a Pixel Buffer Object could have confused the WebGL code to skip binding the buffer used to unpack it, resulting in memory corruption and a potentially exploitable information leak or crash. This vulnerability affects Firefox ESR < 78.9, Firefox < 87, and Thunderbird < 78.9.

Buffer Overflow

Using techniques that built on the slipstream research, a malicious webpage could have s

CVE-2021-23982 6.5 - Medium - March 31, 2021

Using techniques that built on the slipstream research, a malicious webpage could have scanned both an internal network's hosts as well as services running on the user's local machine utilizing WebRTC connections. This vulnerability affects Firefox ESR < 78.9, Firefox < 87, and Thunderbird < 78.9.

Inadequate Encryption Strength

A malicious extension could have opened a popup window lacking an address bar

CVE-2021-23984 6.5 - Medium - March 31, 2021

A malicious extension could have opened a popup window lacking an address bar. The title of the popup lacking an address bar should not be fully controllable, but in this situation was. This could have been used to spoof a website and attempt to trick the user into providing credentials. This vulnerability affects Firefox ESR < 78.9, Firefox < 87, and Thunderbird < 78.9.

Authentication Bypass by Spoofing

Mozilla developers and community members reported memory safety bugs present in Firefox 86 and Firefox ESR 78.8

CVE-2021-23987 8.8 - High - March 31, 2021

Mozilla developers and community members reported memory safety bugs present in Firefox 86 and Firefox ESR 78.8. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox ESR < 78.9, Firefox < 87, and Thunderbird < 78.9.

Buffer Overflow

Mozilla developers reported memory safety bugs present in Firefox 84 and Firefox ESR 78.6

CVE-2021-23964 8.8 - High - February 26, 2021

Mozilla developers reported memory safety bugs present in Firefox 84 and Firefox ESR 78.6. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 85, Thunderbird < 78.7, and Firefox ESR < 78.7.

Buffer Overflow

Mozilla developers reported memory safety bugs present in Firefox 85 and Firefox ESR 78.7

CVE-2021-23978 8.8 - High - February 26, 2021

Mozilla developers reported memory safety bugs present in Firefox 85 and Firefox ESR 78.7. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 86, Thunderbird < 78.8, and Firefox ESR < 78.8.

If a user clicked into a specifically crafted PDF

CVE-2021-23953 4.3 - Medium - February 26, 2021

If a user clicked into a specifically crafted PDF, the PDF reader could be confused into leaking cross-origin information, when said information is served as chunked data. This vulnerability affects Firefox < 85, Thunderbird < 78.7, and Firefox ESR < 78.7.

Using the new logical assignment operators in a JavaScript switch statement could have caused a type confusion

CVE-2021-23954 8.8 - High - February 26, 2021

Using the new logical assignment operators in a JavaScript switch statement could have caused a type confusion, leading to a memory corruption and a potentially exploitable crash. This vulnerability affects Firefox < 85, Thunderbird < 78.7, and Firefox ESR < 78.7.

Object Type Confusion

Performing garbage collection on re-declared JavaScript variables resulted in a user-after-poison, and a potentially exploitable crash

CVE-2021-23960 8.8 - High - February 26, 2021

Performing garbage collection on re-declared JavaScript variables resulted in a user-after-poison, and a potentially exploitable crash. This vulnerability affects Firefox < 85, Thunderbird < 78.7, and Firefox ESR < 78.7.

If Content Security Policy blocked frame navigation

CVE-2021-23968 4.3 - Medium - February 26, 2021

If Content Security Policy blocked frame navigation, the full destination of a redirect served in the frame was reported in the violation report; as opposed to the original frame URI. This could be used to leak sensitive information contained in such URIs. This vulnerability affects Firefox < 86, Thunderbird < 78.8, and Firefox ESR < 78.8.

Generation of Error Message Containing Sensitive Information

As specified in the W3C Content Security Policy draft, when creating a violation report, "User agents need to ensure

CVE-2021-23969 4.3 - Medium - February 26, 2021

As specified in the W3C Content Security Policy draft, when creating a violation report, "User agents need to ensure that the source file is the URL requested by the page, pre-redirects. If thats not possible, user agents need to strip the URL down to an origin to avoid unintentional leakage." Under certain types of redirects, Firefox incorrectly set the source file to be the destination of the redirects. This was fixed to be the redirect destination's origin. This vulnerability affects Firefox < 86, Thunderbird < 78.8, and Firefox ESR < 78.8.

When trying to load a cross-origin resource in an audio/video context a decoding error may have resulted, and the content of

CVE-2021-23973 6.5 - Medium - February 26, 2021

When trying to load a cross-origin resource in an audio/video context a decoding error may have resulted, and the content of that error may have revealed information about the resource. This vulnerability affects Firefox < 86, Thunderbird < 78.8, and Firefox ESR < 78.8.

Generation of Error Message Containing Sensitive Information

Certain blit values provided by the user were not properly constrained leading to a heap buffer overflow on some video drivers

CVE-2020-26971 8.8 - High - January 07, 2021

Certain blit values provided by the user were not properly constrained leading to a heap buffer overflow on some video drivers. This vulnerability affects Firefox < 84, Thunderbird < 78.6, and Firefox ESR < 78.6.

Memory Corruption

Certain input to the CSS Sanitizer confused it, resulting in incorrect components being removed

CVE-2020-26973 8.8 - High - January 07, 2021

Certain input to the CSS Sanitizer confused it, resulting in incorrect components being removed. This could have been used as a sanitizer bypass. This vulnerability affects Firefox < 84, Thunderbird < 78.6, and Firefox ESR < 78.6.

When flex-basis was used on a table wrapper, a StyleGenericFlexBasis object could have been incorrectly cast to the wrong type

CVE-2020-26974 8.8 - High - January 07, 2021

When flex-basis was used on a table wrapper, a StyleGenericFlexBasis object could have been incorrectly cast to the wrong type. This resulted in a heap user-after-free, memory corruption, and a potentially exploitable crash. This vulnerability affects Firefox < 84, Thunderbird < 78.6, and Firefox ESR < 78.6.

Memory Corruption

Using techniques that built on the slipstream research

CVE-2020-26978 6.1 - Medium - January 07, 2021

Using techniques that built on the slipstream research, a malicious webpage could have exposed both an internal network's hosts as well as services running on the user's local machine. This vulnerability affects Firefox < 84, Thunderbird < 78.6, and Firefox ESR < 78.6.

When an extension with the proxy permission registered to receive <all_urls>

CVE-2020-35111 4.3 - Medium - January 07, 2021

When an extension with the proxy permission registered to receive <all_urls>, the proxy.onRequest callback was not triggered for view-source URLs. While web content cannot navigate to such URLs, a user opening View Source could have inadvertently leaked their IP address. This vulnerability affects Firefox < 84, Thunderbird < 78.6, and Firefox ESR < 78.6.

Mozilla developers reported memory safety bugs present in Firefox 83 and Firefox ESR 78.5

CVE-2020-35113 8.8 - High - January 07, 2021

Mozilla developers reported memory safety bugs present in Firefox 83 and Firefox ESR 78.5. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 84, Thunderbird < 78.6, and Firefox ESR < 78.6.

Memory Corruption

In certain circumstances, the MCallGetProperty opcode

CVE-2020-26950 8.8 - High - December 09, 2020

In certain circumstances, the MCallGetProperty opcode can be emitted with unmet assumptions resulting in an exploitable use-after-free condition. This vulnerability affects Firefox < 82.0.3, Firefox ESR < 78.4.1, and Thunderbird < 78.4.2.

Dangling pointer

A parsing and event loading mismatch in Firefox's SVG code could have allowed load events to fire, even after sanitization

CVE-2020-26951 6.1 - Medium - December 09, 2020

A parsing and event loading mismatch in Firefox's SVG code could have allowed load events to fire, even after sanitization. An attacker already capable of exploiting an XSS vulnerability in privileged internal pages could have used this attack to bypass our built-in sanitizer. This vulnerability affects Firefox < 83, Firefox ESR < 78.5, and Thunderbird < 78.5.

XSS

It was possible to cause the browser to enter fullscreen mode without displaying the security UI; thus making it possible to attempt a phishing attack or otherwise confuse the user

CVE-2020-26953 4.3 - Medium - December 09, 2020

It was possible to cause the browser to enter fullscreen mode without displaying the security UI; thus making it possible to attempt a phishing attack or otherwise confuse the user. This vulnerability affects Firefox < 83, Firefox ESR < 78.5, and Thunderbird < 78.5.

Clickjacking

In some cases, removing HTML elements during sanitization would keep existing SVG event handlers and therefore lead to XSS

CVE-2020-26956 6.1 - Medium - December 09, 2020

In some cases, removing HTML elements during sanitization would keep existing SVG event handlers and therefore lead to XSS. This vulnerability affects Firefox < 83, Firefox ESR < 78.5, and Thunderbird < 78.5.

XSS

Firefox did not block execution of scripts with incorrect MIME types when the response was intercepted and cached through a ServiceWorker

CVE-2020-26958 6.1 - Medium - December 09, 2020

Firefox did not block execution of scripts with incorrect MIME types when the response was intercepted and cached through a ServiceWorker. This could lead to a cross-site script inclusion vulnerability, or a Content Security Policy bypass. This vulnerability affects Firefox < 83, Firefox ESR < 78.5, and Thunderbird < 78.5.

XSS

During browser shutdown

CVE-2020-26959 8.8 - High - December 09, 2020

During browser shutdown, reference decrementing could have occured on a previously freed object, resulting in a use-after-free, memory corruption, and a potentially exploitable crash. This vulnerability affects Firefox < 83, Firefox ESR < 78.5, and Thunderbird < 78.5.

Dangling pointer

If the Compact() method was called on an nsTArray

CVE-2020-26960 8.8 - High - December 09, 2020

If the Compact() method was called on an nsTArray, the array could have been reallocated without updating other pointers, leading to a potential use-after-free and exploitable crash. This vulnerability affects Firefox < 83, Firefox ESR < 78.5, and Thunderbird < 78.5.

Dangling pointer

When DNS over HTTPS is in use, it intentionally filters RFC1918 and related IP ranges

CVE-2020-26961 6.5 - Medium - December 09, 2020

When DNS over HTTPS is in use, it intentionally filters RFC1918 and related IP ranges from the responses as these do not make sense coming from a DoH resolver. However when an IPv4 address was mapped through IPv6, these addresses were erroneously let through, leading to a potential DNS Rebinding attack. This vulnerability affects Firefox < 83, Firefox ESR < 78.5, and Thunderbird < 78.5.

Some websites have a feature "Show Password" where clicking a button will change a password field into a textbook field

CVE-2020-26965 6.5 - Medium - December 09, 2020

Some websites have a feature "Show Password" where clicking a button will change a password field into a textbook field, revealing the typed password. If, when using a software keyboard that remembers user input, a user typed their password and used that feature, the type of the password field was changed, resulting in a keyboard layout change and the possibility for the software keyboard to remember the typed password. This vulnerability affects Firefox < 83, Firefox ESR < 78.5, and Thunderbird < 78.5.

Improper Removal of Sensitive Information Before Storage or Transfer

Mozilla developers reported memory safety bugs present in Firefox 82 and Firefox ESR 78.4

CVE-2020-26968 8.8 - High - December 09, 2020

Mozilla developers reported memory safety bugs present in Firefox 82 and Firefox ESR 78.4. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 83, Firefox ESR < 78.5, and Thunderbird < 78.5.

Memory Corruption

When reading SMTP server status codes, Thunderbird writes an integer value to a position on the stack

CVE-2020-26970 8.8 - High - December 09, 2020

When reading SMTP server status codes, Thunderbird writes an integer value to a position on the stack that is intended to contain just one byte. Depending on processor architecture and stack layout, this leads to stack corruption that may be exploitable. This vulnerability affects Thunderbird < 78.5.1.

Memory Corruption

Mozilla developers and community members reported memory safety bugs present in Firefox 81 and Firefox ESR 78.3

CVE-2020-15683 9.8 - Critical - October 22, 2020

Mozilla developers and community members reported memory safety bugs present in Firefox 81 and Firefox ESR 78.3. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox ESR < 78.4, Firefox < 82, and Thunderbird < 78.4.

If an attacker intercepts Thunderbird's initial attempt to perform automatic account setup using the Microsoft Exchange autodiscovery mechanism

CVE-2020-15646 5.9 - Medium - October 08, 2020

If an attacker intercepts Thunderbird's initial attempt to perform automatic account setup using the Microsoft Exchange autodiscovery mechanism, and the attacker sends a crafted response, then Thunderbird sends username and password over https to a server controlled by the attacker. This vulnerability affects Thunderbird < 68.10.0.

Insufficiently Protected Credentials

If Firefox is installed to a user-writable directory, the Mozilla Maintenance Service would execute updater.exe

CVE-2020-15663 8.8 - High - October 01, 2020

If Firefox is installed to a user-writable directory, the Mozilla Maintenance Service would execute updater.exe from the install location with system privileges. Although the Mozilla Maintenance Service does ensure that updater.exe is signed by Mozilla, the version could have been rolled back to a previous version which would have allowed exploitation of an older bug and arbitrary code execution with System Privileges. *Note: This issue only affected Windows operating systems. Other operating systems are unaffected.*. This vulnerability affects Firefox < 80, Thunderbird < 78.2, Thunderbird < 68.12, Firefox ESR < 68.12, and Firefox ESR < 78.2.

Improper Privilege Management

By holding a reference to the eval() function from an about:blank window, a malicious webpage could have gained access to the InstallTrigger object which would

CVE-2020-15664 6.5 - Medium - October 01, 2020

By holding a reference to the eval() function from an about:blank window, a malicious webpage could have gained access to the InstallTrigger object which would allow them to prompt the user to install an extension. Combined with user confusion, this could result in an unintended or malicious extension being installed. This vulnerability affects Firefox < 80, Thunderbird < 78.2, Thunderbird < 68.12, Firefox ESR < 68.12, Firefox ESR < 78.2, and Firefox for Android < 80.

AuthZ

When aborting an operation, such as a fetch, an abort signal may be deleted while alerting the objects to be notified

CVE-2020-15669 8.8 - High - October 01, 2020

When aborting an operation, such as a fetch, an abort signal may be deleted while alerting the objects to be notified. This results in a use-after-free and we presume that with enough effort it could have been exploited to run arbitrary code. This vulnerability affects Firefox ESR < 68.12 and Thunderbird < 68.12.

Dangling pointer

Mozilla developers reported memory safety bugs present in Firefox for Android 79

CVE-2020-15670 8.8 - High - October 01, 2020

Mozilla developers reported memory safety bugs present in Firefox for Android 79. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 80, Firefox ESR < 78.2, Thunderbird < 78.2, and Firefox for Android < 80.

Release of Invalid Pointer or Reference

Mozilla developers reported memory safety bugs present in Firefox 80 and Firefox ESR 78.2

CVE-2020-15673 8.8 - High - October 01, 2020

Mozilla developers reported memory safety bugs present in Firefox 80 and Firefox ESR 78.2. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 81, Thunderbird < 78.3, and Firefox ESR < 78.3.

Release of Invalid Pointer or Reference

Firefox sometimes ran the onload handler for SVG elements

CVE-2020-15676 6.1 - Medium - October 01, 2020

Firefox sometimes ran the onload handler for SVG elements that the DOM sanitizer decided to remove, resulting in JavaScript being executed after pasting attacker-controlled data into a contenteditable element. This vulnerability affects Firefox < 81, Thunderbird < 78.3, and Firefox ESR < 78.3.

XSS

By exploiting an Open Redirect vulnerability on a website, an attacker could have spoofed the site displayed in the download file dialog to show the original site (the one suffering

CVE-2020-15677 6.1 - Medium - October 01, 2020

By exploiting an Open Redirect vulnerability on a website, an attacker could have spoofed the site displayed in the download file dialog to show the original site (the one suffering from the open redirect) rather than the site the file was actually downloaded from. This vulnerability affects Firefox < 81, Thunderbird < 78.3, and Firefox ESR < 78.3.

Open Redirect

When recursing through graphical layers while scrolling, an iterator may have become invalid, resulting in a potential use-after-free

CVE-2020-15678 8.8 - High - October 01, 2020

When recursing through graphical layers while scrolling, an iterator may have become invalid, resulting in a potential use-after-free. This occurs because the function APZCTreeManager::ComputeClippedCompositionBounds did not follow iterator invalidation rules. This vulnerability affects Firefox < 81, Thunderbird < 78.3, and Firefox ESR < 78.3.

Dangling pointer

Using object or embed tags, it was possible to frame other websites, even if they disallowed framing using the X-Frame-Options header

CVE-2020-15648 6.5 - Medium - August 10, 2020

Using object or embed tags, it was possible to frame other websites, even if they disallowed framing using the X-Frame-Options header. This vulnerability affects Thunderbird < 78 and Firefox < 78.0.2.

Clickjacking

By observing the stack trace for JavaScript errors in web workers, it was possible to leak the result of a cross-origin redirect

CVE-2020-15652 6.5 - Medium - August 10, 2020

By observing the stack trace for JavaScript errors in web workers, it was possible to leak the result of a cross-origin redirect. This applied only to content that can be parsed as script. This vulnerability affects Firefox < 79, Firefox ESR < 68.11, Firefox ESR < 78.1, Thunderbird < 68.11, and Thunderbird < 78.1.

Origin Validation Error

An iframe sandbox element with the allow-popups flag could be bypassed when using noopener links

CVE-2020-15653 6.5 - Medium - August 10, 2020

An iframe sandbox element with the allow-popups flag could be bypassed when using noopener links. This could have led to security issues for websites relying on sandbox configurations that allowed popups and hosted arbitrary content. This vulnerability affects Firefox ESR < 78.1, Firefox < 79, and Thunderbird < 78.1.

When in an endless loop

CVE-2020-15654 6.5 - Medium - August 10, 2020

When in an endless loop, a website specifying a custom cursor using CSS could make it look like the user is interacting with the user interface, when they are not. This could lead to a perceived broken state, especially when interactions with existing browser dialogs and warnings do not work. This vulnerability affects Firefox ESR < 78.1, Firefox < 79, and Thunderbird < 78.1.

Infinite Loop

A redirected HTTP request

CVE-2020-15655 6.5 - Medium - August 10, 2020

A redirected HTTP request which is observed or modified through a web extension could bypass existing CORS checks, leading to potential disclosure of cross-origin information. This vulnerability affects Firefox ESR < 78.1, Firefox < 79, and Thunderbird < 78.1.

Information Disclosure

JIT optimizations involving the Javascript arguments object could confuse later optimizations

CVE-2020-15656 8.8 - High - August 10, 2020

JIT optimizations involving the Javascript arguments object could confuse later optimizations. This risk was already mitigated by various precautions in the code, resulting in this bug rated at only moderate severity. This vulnerability affects Firefox ESR < 78.1, Firefox < 79, and Thunderbird < 78.1.

Object Type Confusion

The code for downloading files did not properly take care of special characters

CVE-2020-15658 6.5 - Medium - August 10, 2020

The code for downloading files did not properly take care of special characters, which led to an attacker being able to cut off the file ending at an earlier position, leading to a different file type being downloaded than shown in the dialog. This vulnerability affects Firefox ESR < 78.1, Firefox < 79, and Thunderbird < 78.1.

Improper Check for Unusual or Exceptional Conditions

Mozilla developers and community members reported memory safety bugs present in Firefox 78 and Firefox ESR 78.0

CVE-2020-15659 8.8 - High - August 10, 2020

Mozilla developers and community members reported memory safety bugs present in Firefox 78 and Firefox ESR 78.0. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 79, Firefox ESR < 68.11, Firefox ESR < 78.1, Thunderbird < 68.11, and Thunderbird < 78.1.

Memory Corruption

If Thunderbird is configured to use STARTTLS for an IMAP server

CVE-2020-12398 7.5 - High - July 09, 2020

If Thunderbird is configured to use STARTTLS for an IMAP server, and the server sends a PREAUTH response, then Thunderbird will continue with an unencrypted connection, causing email data to be sent without protection. This vulnerability affects Thunderbird < 68.9.0.

Missing Encryption of Sensitive Data

NSS has shown timing differences when performing DSA signatures, which was exploitable and could eventually leak private keys

CVE-2020-12399 4.4 - Medium - July 09, 2020

NSS has shown timing differences when performing DSA signatures, which was exploitable and could eventually leak private keys. This vulnerability affects Thunderbird < 68.9.0, Firefox < 77, and Firefox ESR < 68.9.

Side Channel Attack

When browsing a malicious page, a race condition in our SharedWorkerService could occur and lead to a potentially exploitable crash

CVE-2020-12405 5.3 - Medium - July 09, 2020

When browsing a malicious page, a race condition in our SharedWorkerService could occur and lead to a potentially exploitable crash. This vulnerability affects Thunderbird < 68.9.0, Firefox < 77, and Firefox ESR < 68.9.

Dangling pointer

Mozilla Developer Iain Ireland discovered a missing type check during unboxed objects removal, resulting in a crash

CVE-2020-12406 8.8 - High - July 09, 2020

Mozilla Developer Iain Ireland discovered a missing type check during unboxed objects removal, resulting in a crash. We presume that with enough effort that it could be exploited to run arbitrary code. This vulnerability affects Thunderbird < 68.9.0, Firefox < 77, and Firefox ESR < 68.9.

Insufficient Verification of Data Authenticity

Due to confusion about ValueTags on JavaScript Objects

CVE-2020-12417 8.8 - High - July 09, 2020

Due to confusion about ValueTags on JavaScript Objects, an object may pass through the type barrier, resulting in memory corruption and a potentially exploitable crash. *Note: this issue only affects Firefox on ARM64 platforms.* This vulnerability affects Firefox ESR < 68.10, Firefox < 78, and Thunderbird < 68.10.0.

Buffer Overflow

Manipulating individual parts of a URL object could have caused an out-of-bounds read, leaking process memory to malicious JavaScript

CVE-2020-12418 6.5 - Medium - July 09, 2020

Manipulating individual parts of a URL object could have caused an out-of-bounds read, leaking process memory to malicious JavaScript. This vulnerability affects Firefox ESR < 68.10, Firefox < 78, and Thunderbird < 68.10.0.

Out-of-bounds Read

When processing callbacks

CVE-2020-12419 8.8 - High - July 09, 2020

When processing callbacks that occurred during window flushing in the parent process, the associated window may die; causing a use-after-free condition. This could have led to memory corruption and a potentially exploitable crash. This vulnerability affects Firefox ESR < 68.10, Firefox < 78, and Thunderbird < 68.10.0.

Dangling pointer

When trying to connect to a STUN server

CVE-2020-12420 8.8 - High - July 09, 2020

When trying to connect to a STUN server, a race condition could have caused a use-after-free of a pointer, leading to memory corruption and a potentially exploitable crash. This vulnerability affects Firefox ESR < 68.10, Firefox < 78, and Thunderbird < 68.10.0.

Dangling pointer

When performing add-on updates

CVE-2020-12421 6.5 - Medium - July 09, 2020

When performing add-on updates, certificate chains terminating in non-built-in-roots were rejected (even if they were legitimately added by an administrator.) This could have caused add-ons to become out-of-date silently without notification to the user. This vulnerability affects Firefox ESR < 68.10, Firefox < 78, and Thunderbird < 68.10.0.

Improper Certificate Validation

An integer overflow vulnerability in the Skia library when allocating memory for edge builders on some systems with at least 16 GB of RAM

CVE-2018-12371 8.8 - High - July 09, 2020

An integer overflow vulnerability in the Skia library when allocating memory for edge builders on some systems with at least 16 GB of RAM. This results in the use of uninitialized memory, resulting in a potentially exploitable crash. This vulnerability affects Firefox ESR < 60.1, Thunderbird < 60, and Firefox < 61.

Integer Overflow or Wraparound

A buffer overflow could occur when parsing and validating SCTP chunks in WebRTC

CVE-2020-6831 9.8 - Critical - May 26, 2020

A buffer overflow could occur when parsing and validating SCTP chunks in WebRTC. This could have led to memory corruption and a potentially exploitable crash. This vulnerability affects Firefox ESR < 68.8, Firefox < 76, and Thunderbird < 68.8.0.

Classic Buffer Overflow

A race condition when running shutdown code for Web Worker led to a use-after-free vulnerability

CVE-2020-12387 8.1 - High - May 26, 2020

A race condition when running shutdown code for Web Worker led to a use-after-free vulnerability. This resulted in a potentially exploitable crash. This vulnerability affects Firefox ESR < 68.8, Firefox < 76, and Thunderbird < 68.8.0.

Race Condition

The 'Copy as cURL' feature of Devtools' network tab did not properly escape the HTTP POST data of a request

CVE-2020-12392 5.5 - Medium - May 26, 2020

The 'Copy as cURL' feature of Devtools' network tab did not properly escape the HTTP POST data of a request, which can be controlled by the website. If a user used the 'Copy as cURL' feature and pasted the command into a terminal, it could have resulted in the disclosure of local files. This vulnerability affects Firefox ESR < 68.8, Firefox < 76, and Thunderbird < 68.8.0.

Information Disclosure

Mozilla developers and community members reported memory safety bugs present in Firefox 75 and Firefox ESR 68.7

CVE-2020-12395 9.8 - Critical - May 26, 2020

Mozilla developers and community members reported memory safety bugs present in Firefox 75 and Firefox ESR 68.7. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox ESR < 68.8, Firefox < 76, and Thunderbird < 68.8.0.

Buffer Overflow

By encoding Unicode whitespace characters within the From email header, an attacker can spoof the sender email address

CVE-2020-12397 4.3 - Medium - May 22, 2020

By encoding Unicode whitespace characters within the From email header, an attacker can spoof the sender email address that Thunderbird displays. This vulnerability affects Thunderbird < 68.8.0.

Origin Validation Error

Under certain conditions, when running the nsDocShell destructor, a race condition can cause a use-after-free

CVE-2020-6819 8.1 - High - April 24, 2020

Under certain conditions, when running the nsDocShell destructor, a race condition can cause a use-after-free. We are aware of targeted attacks in the wild abusing this flaw. This vulnerability affects Thunderbird < 68.7.0, Firefox < 74.0.1, and Firefox ESR < 68.6.1.

Dangling pointer

Under certain conditions, when handling a ReadableStream, a race condition can cause a use-after-free

CVE-2020-6820 8.1 - High - April 24, 2020

Under certain conditions, when handling a ReadableStream, a race condition can cause a use-after-free. We are aware of targeted attacks in the wild abusing this flaw. This vulnerability affects Thunderbird < 68.7.0, Firefox < 74.0.1, and Firefox ESR < 68.6.1.

Double-free

When reading from areas partially or fully outside the source resource with WebGL's <code>copyTexSubImage</code> method

CVE-2020-6821 7.5 - High - April 24, 2020

When reading from areas partially or fully outside the source resource with WebGL's <code>copyTexSubImage</code> method, the specification requires the returned values be zero. Previously, this memory was uninitialized, leading to potentially sensitive data disclosure. This vulnerability affects Thunderbird < 68.7.0, Firefox ESR < 68.7, and Firefox < 75.

Buffer Overflow

On 32-bit builds, an out of bounds write could have occurred when processing an image larger than 4 GB in <code>GMPDecodeData</code>

CVE-2020-6822 8.8 - High - April 24, 2020

On 32-bit builds, an out of bounds write could have occurred when processing an image larger than 4 GB in <code>GMPDecodeData</code>. It is possible that with enough effort this could have been exploited to run arbitrary code. This vulnerability affects Thunderbird < 68.7.0, Firefox ESR < 68.7, and Firefox < 75.

Memory Corruption

Mozilla developers and community members Tyson Smith and Christian Holler reported memory safety bugs present in Firefox 74 and Firefox ESR 68.6

CVE-2020-6825 9.8 - Critical - April 24, 2020

Mozilla developers and community members Tyson Smith and Christian Holler reported memory safety bugs present in Firefox 74 and Firefox ESR 68.6. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Thunderbird < 68.7.0, Firefox ESR < 68.7, and Firefox < 75.

Buffer Overflow

When removing data about an origin whose tab was recently closed

CVE-2020-6805 8.8 - High - March 25, 2020

When removing data about an origin whose tab was recently closed, a use-after-free could occur in the Quota manager, resulting in a potentially exploitable crash. This vulnerability affects Thunderbird < 68.6, Firefox < 74, Firefox < ESR68.6, and Firefox ESR < 68.6.

Dangling pointer

By carefully crafting promise resolutions

CVE-2020-6806 8.8 - High - March 25, 2020

By carefully crafting promise resolutions, it was possible to cause an out-of-bounds read off the end of an array resized during script execution. This could have led to memory corruption and a potentially exploitable crash. This vulnerability affects Thunderbird < 68.6, Firefox < 74, Firefox < ESR68.6, and Firefox ESR < 68.6.

Out-of-bounds Read

When a device was changed while a stream was about to be destroyed

CVE-2020-6807 8.8 - High - March 25, 2020

When a device was changed while a stream was about to be destroyed, the <code>stream-reinit</code> task may have been executed after the stream was destroyed, causing a use-after-free and a potentially exploitable crash. This vulnerability affects Thunderbird < 68.6, Firefox < 74, Firefox < ESR68.6, and Firefox ESR < 68.6.

Dangling pointer

The 'Copy as cURL' feature of Devtools' network tab did not properly escape the HTTP method of a request

CVE-2020-6811 8.8 - High - March 25, 2020

The 'Copy as cURL' feature of Devtools' network tab did not properly escape the HTTP method of a request, which can be controlled by the website. If a user used the 'Copy as Curl' feature and pasted the command into a terminal, it could have resulted in command injection and arbitrary command execution. This vulnerability affects Thunderbird < 68.6, Firefox < 74, Firefox < ESR68.6, and Firefox ESR < 68.6.

Injection

The first time AirPods are connected to an iPhone, they become named after the user's name by default (e.g

CVE-2020-6812 5.3 - Medium - March 25, 2020

The first time AirPods are connected to an iPhone, they become named after the user's name by default (e.g. Jane Doe's AirPods.) Websites with camera or microphone permission are able to enumerate device names, disclosing the user's name. To resolve this issue, Firefox added a special case that renames devices containing the substring 'AirPods' to simply 'AirPods'. This vulnerability affects Thunderbird < 68.6, Firefox < 74, Firefox < ESR68.6, and Firefox ESR < 68.6.

Information Disclosure

Mozilla developers reported memory safety bugs present in Firefox and Thunderbird 68.5

CVE-2020-6814 9.8 - Critical - March 25, 2020

Mozilla developers reported memory safety bugs present in Firefox and Thunderbird 68.5. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Thunderbird < 68.6, Firefox < 74, Firefox < ESR68.6, and Firefox ESR < 68.6.

Buffer Overflow

When deriving an identifier for an email message, uninitialized memory was used in addition to the message contents

CVE-2020-6792 4.3 - Medium - March 02, 2020

When deriving an identifier for an email message, uninitialized memory was used in addition to the message contents. This vulnerability affects Thunderbird < 68.5.

Missing Initialization of Resource

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