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.
This attack-focused weakness is caused by incorrectly implemented authentication schemes that are subject to spoofing attacks.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| H2o | Dena | * | 2024-10-10 (excluding) |