Vulnerability · Published Oct 11, 2024 · Assigned by GitHub_M

CVE-2024-45403H2O assertion failure when HTTP/3 requests are cancelled

Low 3.7

In plain English

A low-severity security flaw in h2o from h2o. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 51% of all known vulnerabilities).

Severity (CVSS 3.1)3.7Low

Exploit odds (30 days)0.7%top 48.5% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

h2o is an HTTP server with support for HTTP/1.x, HTTP/2 and HTTP/3. When h2o is configured as a reverse proxy and HTTP/3 requests are cancelled by the client, h2o might crash due to an assertion failure. The crash can be exploited by an attacker to mount a Denial-of-Service attack. By default, the h2o standalone server automatically restarts, minimizing the impact. However, HTTP requests that were served concurrently will still be disrupted. The vulnerability has been addressed in commit 1ed32b2. Users may disable the use of HTTP/3 to mitigate the issue.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Ubuntu:24.04:LTS	h2o	no fix listed	UBUNTU-CVE-2024-45403

Affected products (as reported)

Vendor	Product	Versions
h2o	h2o	>= 16b13eee8ad7895b4fe3fcbcabee53bd52782562, < 1ed32b23f999acf0c5029f09c8525f93eb1d354c

Weakness: CWE-617 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L

References

https://github.com/h2o/h2o/security/advisories/GHSA-4xp5-3jhc-3m92 x_refsource_CONFIRM
https://github.com/h2o/h2o/commit/16b13eee8ad7895b4fe3fcbcabee53bd52782562 x_refsource_MISC
https://github.com/h2o/h2o/commit/1ed32b23f999acf0c5029f09c8525f93eb1d354c x_refsource_MISC
https://h2o.examp1e.net/configure/http3_directives.html x_refsource_MISC