Home/CVE/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
CVE

CVE-2024-45403

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

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.

LOW · CVSS 3.7 EPSS 0.0033
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  • No active-exploitation, high-EPSS, or public-exploit signals - routine patching cadence
Sigma rules0 YARA rules0
⬡

Weakness Classification

CWE-617Reachable Assertion
▤

Affected Products & Versions

1
dena h2o>= 2024-06-18 and < 2024-09-04
▣

Scoring & Timeline

3.7
LOW · CVSS v3.1 · security-advisories@github.com
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD11 Oct 2024 · 03:15 PM
CVSS VectorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
SSVC triage · cisa-vulnrichment
Exploitation
none
Automatable
no
Technical impact
partial
SSVC asks the questions that actually drive patch urgency: is it being exploited, can attacks be automated, and how total is the impact.
🔗

References & Sources

4
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
https://github.com/h2o/h2o/commit/16b13eee8ad7895b4fe3fcbcabee53bd52782562Patch
https://github.com/h2o/h2o/commit/1ed32b23f999acf0c5029f09c8525f93eb1d354cPatch
https://github.com/h2o/h2o/security/advisories/GHSA-4xp5-3jhc-3m92Vendor Advisory
https://h2o.examp1e.net/configure/http3_directives.htmlProduct
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