Dena H2o
By the Year
In 2024 there have been 0 vulnerabilities in Dena H2o . Last year H2o had 4 security vulnerabilities published. Right now, H2o is on track to have less security vulnerabilities in 2024 than it did last year.
| Year | Vulnerabilities | Average Score |
|---|---|---|
| 2024 | 0 | 0.00 |
| 2023 | 4 | 7.48 |
| 2022 | 1 | 5.90 |
| 2021 | 0 | 0.00 |
| 2020 | 0 | 0.00 |
| 2019 | 0 | 0.00 |
| 2018 | 1 | 9.80 |
It may take a day or so for new H2o 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 Dena H2o Security Vulnerabilities
h2o is an HTTP server with support for HTTP/1.x, HTTP/2 and HTTP/3
CVE-2023-50247
7.5 - High
- December 12, 2023
h2o is an HTTP server with support for HTTP/1.x, HTTP/2 and HTTP/3. The QUIC stack (quicly), as used by H2O up to commit 43f86e5 (in version 2.3.0-beta and prior), is susceptible to a state exhaustion attack. When H2O is serving HTTP/3, a remote attacker can exploit this vulnerability to progressively increase the memory retained by the QUIC stack. This can eventually cause H2O to abort due to memory exhaustion. The vulnerability has been resolved in commit d67e81d03be12a9d53dc8271af6530f40164cd35. HTTP/1 and HTTP/2 are not affected by this vulnerability as they do not use QUIC. Administrators looking to mitigate this issue without upgrading can disable HTTP/3 support.
Allocation of Resources Without Limits or Throttling
h2o is an HTTP server with support for HTTP/1.x, HTTP/2 and HTTP/3
CVE-2023-41337
6.7 - Medium
- December 12, 2023
h2o is an HTTP server with support for HTTP/1.x, HTTP/2 and HTTP/3. In version 2.3.0-beta2 and prior, when h2o is configured to listen to multiple addresses or ports with each of them using different backend servers managed by multiple entities, a malicious backend entity that also has the opportunity to observe or inject packets exchanged between the client and h2o may misdirect HTTPS requests going to other backends and observe the contents of that HTTPS request being sent. The attack involves a victim client trying to resume a TLS connection and an attacker redirecting the packets to a different address or port than that intended by the client. The attacker must already have been configured by the administrator of h2o to act as a backend to one of the addresses or ports that the h2o instance listens to. Session IDs and tickets generated by h2o are not bound to information specific to the server address, port, or the X.509 certificate, and therefore it is possible for an attacker to force the victim connection to wrongfully resume against a different server address or port on which the same h2o instance is listening. Once a TLS session is misdirected to resume to a server address / port that is configured to use an attacker-controlled server as the backend, depending on the configuration, HTTPS requests from the victim client may be forwarded to the attacker's server. An H2O instance is vulnerable to this attack only if the instance is configured to listen to different addresses or ports using the listen directive at the host level and the instance is configured to connect to backend servers managed by multiple entities. A patch is available at commit 35760540337a47e5150da0f4a66a609fad2ef0ab. As a workaround, one may stop using using host-level listen directives in favor of global-level ones.
Improper Verification of Cryptographic Signature
The HTTP/2 protocol
CVE-2023-44487
7.5 - High
- October 10, 2023
The HTTP/2 protocol allows a denial of service (server resource consumption) because request cancellation can reset many streams quickly, as exploited in the wild in August through October 2023.
Resource Exhaustion
H2O is an HTTP server
CVE-2023-30847
8.2 - High
- April 27, 2023
H2O is an HTTP server. In versions 2.3.0-beta2 and prior, when the reverse proxy handler tries to processes a certain type of invalid HTTP request, it tries to build an upstream URL by reading from uninitialized pointer. This behavior can lead to crashes or leak of information to back end HTTP servers. Pull request number 3229 fixes the issue. The pull request has been merged to the `master` branch in commit f010336. Users should upgrade to commit f010336 or later.
Access of Uninitialized Pointer
h2o is an open source http server
CVE-2021-43848
5.9 - Medium
- February 01, 2022
h2o is an open source http server. In code prior to the `8c0eca3` commit h2o may attempt to access uninitialized memory. When receiving QUIC frames in certain order, HTTP/3 server-side implementation of h2o can be misguided to treat uninitialized memory as HTTP/3 frames that have been received. When h2o is used as a reverse proxy, an attacker can abuse this vulnerability to send internal state of h2o to backend servers controlled by the attacker or third party. Also, if there is an HTTP endpoint that reflects the traffic sent from the client, an attacker can use that reflector to obtain internal state of h2o. This internal state includes traffic of other connections in unencrypted form and TLS session tickets. This vulnerability exists in h2o server with HTTP/3 support, between commit 93af138 and d1f0f65. None of the released versions of h2o are affected by this vulnerability. There are no known workarounds. Users of unreleased versions of h2o using HTTP/3 are advised to upgrade immediately.
Use of Uninitialized Resource
Buffer overflow in H2O version 2.2.4 and earlier
CVE-2018-0608
9.8 - Critical
- June 26, 2018
Buffer overflow in H2O version 2.2.4 and earlier allows remote attackers to execute arbitrary code or cause a denial of service (DoS) via unspecified vectors.
Buffer Overflow
Buffer overflow in H2O version 2.2.2 and earlier
CVE-2017-10869
7.5 - High
- December 22, 2017
Buffer overflow in H2O version 2.2.2 and earlier allows remote attackers to cause a denial-of-service in the server via unspecified vectors.
Buffer Overflow
H2O version 2.2.3 and earlier
CVE-2017-10872
6.5 - Medium
- December 22, 2017
H2O version 2.2.3 and earlier allows remote attackers to cause a denial of service in the server via unspecified vectors.
Range Error
H2O version 2.2.3 and earlier
CVE-2017-10908
7.5 - High
- December 22, 2017
H2O version 2.2.3 and earlier allows remote attackers to cause a denial of service in the server via specially crafted HTTP/2 header.
Improper Input Validation
H2O version 2.2.2 and earlier
CVE-2017-10868
7.5 - High
- December 22, 2017
H2O version 2.2.2 and earlier allows remote attackers to cause a denial of service in the server via specially crafted HTTP/1 header.
Improper Input Validation
Use-after-free vulnerability in H2O
CVE-2016-7835
9.1 - Critical
- June 09, 2017
Use-after-free vulnerability in H2O allows remote attackers to cause a denial-of-service (DoS) or obtain server certificate private keys and possibly other information.
Dangling pointer
lib/http2/connection.c in H2O before 1.7.3 and 2.x before 2.0.0-beta5 mishandles HTTP/2 disconnection, which
CVE-2016-4817
7.5 - High
- June 19, 2016
lib/http2/connection.c in H2O before 1.7.3 and 2.x before 2.0.0-beta5 mishandles HTTP/2 disconnection, which allows remote attackers to cause a denial of service (use-after-free and application crash) or possibly execute arbitrary code via a crafted packet.<a href="http://cwe.mitre.org/data/definitions/416.html">CWE-416: Use After Free</a>
CRLF injection vulnerability in the on_req function in lib/handler/redirect.c in H2O before 1.6.2 and 1.7.x before 1.7.0-beta3
CVE-2016-1133
3.7 - Low
- January 16, 2016
CRLF injection vulnerability in the on_req function in lib/handler/redirect.c in H2O before 1.6.2 and 1.7.x before 1.7.0-beta3 allows remote attackers to inject arbitrary HTTP headers and conduct HTTP response splitting attacks via a crafted URI.<a href="https://cwe.mitre.org/data/definitions/93.html">CWE-93: Improper Neutralization of CRLF Sequences ('CRLF Injection')</a>
