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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| rofl0r | proxychains-ng | ≤ 4.17 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | proxychains-ng | 4.17-3.1 | — |
| Debian 13 | proxychains-ng | No fix yet | — |
| Debian 12 | proxychains-ng | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | proxychains-ng | No fix yet | — |
| Ubuntu 26.04 LTS | proxychains-ng | No fix yet | — |
| Ubuntu 25.10 | proxychains-ng | No fix yet | — |
| Ubuntu 24.04 LTS | proxychains-ng | No fix yet | — |
| Ubuntu 22.04 LTS | proxychains-ng | No fix yet | — |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | proxychains-ng | No fix yet | — |
| Ubuntu 18.04 LTS | proxychains-ng | No fix yet | — |
References
- https://github.com/marlinkcyber/advisories/blob/main/advisories/MCSAID-2025-008-proxychains-ng-stack-buffer-overflow-proxy_from_string.md technical-description exploit
- https://github.com/rofl0r/proxychains-ng/issues/606 issue-tracking
- https://github.com/httpsgithu/proxychains-ng/commit/cc005b7 patch
- https://www.vulncheck.com/advisories/rofl0r-proxychains-ng-stack-based-buffer-overflow third-party-advisory