CVE-2025-31135 (GCVE-0-2025-31135)
Vulnerability from cvelistv5 – Published: 2025-04-01 22:03 – Updated: 2026-01-28 22:27
VLAI
EPSS
VEX
Title
Go-Guerrilla SMTP Daemon allows the PROXY command to be sent multiple times
Summary
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.
Severity
5.3 (Medium)
SSVC
Exploitation: none
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2025-04-02 13:47 UTC
CWE
- CWE-20 - Improper Input Validation
Assigner
GitHub_M
CNA
References
2 references
| URL | Tags |
|---|---|
| https://github.com/phires/go-guerrilla/security/a… | x_refsource_CONFIRM |
| https://github.com/phires/go-guerrilla/commit/d08… | x_refsource_MISC |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| phires | go-guerrilla |
Affected:
< 1.6.7
|
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