mozilla firefox CVE-2020-6820 vulnerability in Mozilla Products
Published on April 24, 2020

product logo product logo product logo
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.

Vendor Advisory NVD

Known Exploited Vulnerability

This Mozilla Firefox 74 and Firefox ESR 68.6 ReadableStream vulnerability is part of CISA's list of Known Exploited Vulnerabilities. A race condition can cause a use-after-free when handling a ReadableStream. This vulnerability affects Thunderbird < 68.7.0, Firefox < 74.0.1, and Firefox ESR < 68.6.1.

The following remediation steps are recommended / required by May 3, 2022: Apply updates per vendor instructions.

Vulnerability Analysis

CVE-2020-6820 is exploitable with network access, and does not require authorization privileges or user interaction. This vulnerability is consided to have a high level of attack complexity. This vulnerability is known to be actively exploited by threat actors. The potential impact of an exploit of this vulnerability is considered to be very high.

Attack Vector:
NETWORK
Attack Complexity:
HIGH
Privileges Required:
NONE
User Interaction:
NONE
Scope:
UNCHANGED
Confidentiality Impact:
HIGH
Integrity Impact:
HIGH
Availability Impact:
HIGH

Weakness Type

What is a Race Condition Vulnerability?

The program contains a code sequence that can run concurrently with other code, and the code sequence requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence that is operating concurrently.

CVE-2020-6820 has been classified to as a Race Condition vulnerability or weakness.


Products Associated with CVE-2020-6820

Want to know whenever a new CVE is published for Mozilla products? stack.watch will email you.

 
 
 

Affected Versions

Mozilla Thunderbird: Mozilla Firefox: Mozilla Firefox ESR:

Exploit Probability

EPSS
5.00%
Percentile
89.55%

EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.