CVE-2024-45397
highpriority · track · 30EPSS 0.004 · 38 %ileEUUSEPSS · scored 2026-10-28
h2o is an HTTP server with support for HTTP/1.x, HTTP/2 and HTTP/3. When an HTTP request using TLS/1.3 early data on top of TCP Fast Open or QUIC 0-RTT packets is received and the IP-address-based access control is used, the access control does not detect and prohibit HTTP requests conveyed by packets with a spoofed source address. This behavior allows attackers on the network to execute HTTP requests from addresses that are otherwise rejected by the address-based access control. The vulnerability has been addressed in commit 15ed15a. Users may disable the use of TCP FastOpen and QUIC to mitigate the issue.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 5.9–7.5
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (2)
Products and version ranges known to be affected.
also known as (2)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (10)
External citations — patches, advisories, analysis.
- https://cxsecurity.com/cveshow/CVE-2024-45397/cnnvd
- https://github.com/h2o/h2o/commit/15ed15a2efb83a77bb4baaa5a119e639c2f6898acnnvd
- https://github.com/h2o/h2o/security/advisories/GHSA-jf2c-xjcp-wg4ccnnvd
- https://h2o.examp1e.net/configure/cnnvd
- https://github.com/h2o/h2o/commit/15ed15a2efb83a77bb4baaa5a119e639c2f6898aenisa_euvd
- https://github.com/h2o/h2o/security/advisories/GHSA-jf2c-xjcp-wg4cenisa_euvd
- https://h2o.examp1e.net/configure/http3_directives.htmlenisa_euvd
- https://github.com/h2o/h2o/commit/15ed15a2efb83a77bb4baaa5a119e639c2f6898aPatchnvd
Attackers weaponise vulnerabilities like this against internet-exposed services. See what is exposed on your perimeter with a free passive scan.
Free scan