CVE-2025-34451 rofl0r/proxychains-ng <= 4.17 Stack-based Buffer Overflow
A stack-based buffer overflow in proxychains-ng allows attackers to cause denial of service or potentially execute code via crafted proxy configuration entries.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-34451?
CVE-2025-34451 is a medium-severity memory corruption vulnerability in rofl0r proxychains-ng, published on 18 Dec 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
rofl0r/proxychains-ng versions up to and including 4.17 and prior to commit cc005b7 contain a stack-based buffer overflow vulnerability in the function proxy_from_string() located in src/libproxychains.c. When parsing crafted proxy configuration entries containing overly long username or password fields, the application may write beyond the bounds of fixed-size stack buffers, leading to memory corruption or crashes. This vulnerability may allow denial of service and, under certain conditions, could be leveraged for further exploitation depending on the execution environment and applied mitigations.
Which versions are affected by CVE-2025-34451?
It affects 1 product.
Products include Proxychains-Ng Project Proxychains-Ng.
How do I fix CVE-2025-34451?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2025-34451 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-34451 exists.
Other vulnerabilities in rofl0r proxychains-ng
Sources
Also known as DEBIAN-CVE-2025-34451, GHSA-8qj4-vcg9-jq63, UBUNTU-CVE-2025-34451.