CVE-2024-45403
low-risk
Published 2024-10-11
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.
Do I need to act?
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0.33% chance of exploitation
EPSS score — low exploit probability
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Not on CISA KEV list
No confirmed active exploitation reported to CISA
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Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
3
CVSS 3.7/10
Low
NETWORK
/ HIGH complexity
Affected Products (1)
H2O
Affected Vendors
References (4)
19
/ 100
low-risk
Severity
13/34 · Low
Exploitability
1/34 · Minimal
Exposure
5/34 · Minimal