vulnerability
Debian: CVE-2024-45397: h2o -- security update
| Severity | CVSS | Published | Added | Modified |
|---|---|---|---|---|
| 7 | (AV:N/AC:M/Au:N/C:C/I:N/A:N) | Oct 11, 2024 | May 15, 2025 | Mar 30, 2026 |
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.
Solution
2026 Global Threat Landscape Report
The predictive window has collapsed. Exploitation follows disclosure in days. See how attackers are accelerating and how to stay ahead.