CVE-2024-35175 is a medium-severity (CVSS 5.3) CWE-345 vulnerability in github.com/tg123/sshpiper. A fix is available for github.com/tg123/sshpiper — see the affected versions and patch details below.
sshpiper's Enabling of Proxy Protocol without proper feature flagging allows faking source address
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
Exploitation and automatability from CISA’s SSVC triage for CVE-2024-35175.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
github.com/tg123/sshpiperReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Summary
The way the proxy protocol listener is implemented in sshpiper can allow an attacker to forge their connecting address.
Details
This commit added the proxy protocol listener as the only listener in sshpiper, with no option to toggle this functionality off. This means that any connection that sshpiper is directly (or in some cases indirectly) exposed to can use proxy protocol to forge its source address.
PoC
You can use a configuration like this in HAProxy:
listen w-send-proxy
mode tcp
log global
option tcplog
bind *:27654
tcp-request connection set-src ipv4(1.1.1.1)
server app1 ssh-piper-hostname:22 send-proxy
When connecting through HAProxy, sshpiper will log connections as originating from 1.1.1.1. The proxy protocol data is designed to survive multiple load balancers or proxies and pass through to sshpiper at the end, so it should only be enabled trusted environments. This should be behind a configuration option or startup flag to prevent abuse when public connections can be made to sshpiper.
This is also backed up by the specification for proxy protocol:
The receiver MUST be configured to only receive the protocol described in this specification and MUST not try to guess whether the protocol header is present or not. This means that the protocol explicitly prevents port sharing between public and private access. Otherwise it would open a major security breach by allowing untrusted parties to spoof their connection addresses. The receiver SHOULD ensure proper access filtering so that only trusted proxies are allowed to use this protocol.
Impact
Any users of sshpiper who need logs from it for whitelisting/rate limiting/security investigations could have them become much less useful if an attacker is sending a spoofed source address.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/tg123/sshpiper | ≥ 1.0.50&&< 1.3.0 | 1.3.0go get github.com/tg123/sshpiper@v1.3.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/tg123/sshpiper, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/tg123/sshpiper to 1.3.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-35175 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
Frequently Asked Questions
Is CVE-2024-35175 in your dependencies?
Find it across Go, including transitive dependencies.