Security Advisory

CVE-2025-31135

CVE vulnerability detail — eXtreme Datacenter Security Operations

Published 2025-04-01 22:03:09
Last updated 2026-01-28 22:27:22
Assigner GitHub_M
State PUBLISHED

Description

Go-Guerrilla SMTP Daemon is a lightweight SMTP server written in Go. Prior to 1.6.7, when ProxyOn is enabled, the PROXY command will be accepted multiple times, with later invocations overriding earlier ones. The proxy protocol only supports one initial PROXY header; anything after that is considered part of the exchange between client and server, so the client is free to send further PROXY commands with whatever data it pleases. go-guerrilla will treat these as coming from the reverse proxy, allowing a client to spoof its IP address. This vulnerability is fixed in 1.6.7.