Vulnerability · Published Oct 11, 2024 · Assigned by GitHub_M

CVE-2024-45397H2O alllows bypassing address-based access control with 0-RTT

Medium 5.9

In plain English

A medium-severity improper access control 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 0.4% (higher than 38% of all known vulnerabilities).

Severity (CVSS 3.1)5.9Medium

Exploit odds (30 days)0.4%top 61.5% 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 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.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Debian:12	h2o	no fix listed	DEBIAN-CVE-2024-45397
Ubuntu:24.04:LTS	h2o	no fix listed	UBUNTU-CVE-2024-45397

Affected products (as reported)

Vendor	Product	Versions
h2o	h2o	< 15ed15a2efb83a77bb4baaa5a119e639c2f6898a

Weakness: CWE-284 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

References

https://github.com/h2o/h2o/security/advisories/GHSA-jf2c-xjcp-wg4c x_refsource_CONFIRM
https://github.com/h2o/h2o/commit/15ed15a2efb83a77bb4baaa5a119e639c2f6898a x_refsource_MISC
https://h2o.examp1e.net/configure/http3_directives.html x_refsource_MISC