CVE-2025-34451

Name: CVE-2025-34451
Creator: NVD / NIST
Published: 2025-12-18T22:15:56.32+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.9/10EPSS 0.22%

Last modified Jun 17, 2026

CVE-2025-34451 is a medium-severity vulnerability rated 6.9/10 on the CVSS scale. 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. EPSS estimates a 0.22% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

7.8/10

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

CVSS 4.0

6.9/10

CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS Probability

0.22%

12.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Proxychains-Ng Project	Proxychains-Ng	<= 4.17

References

https://github.com/httpsgithu/proxychains-ng/commit/cc005b7Patch
https://github.com/marlinkcyber/advisories/blob/main/advisories/MCSAID-2025-008-proxychains-ng-stack-buffer-overflow-proxy_from_string.mdExploit, Third Party Advisory
https://github.com/rofl0r/proxychains-ng/issues/606Exploit, Patch
https://www.vulncheck.com/advisories/rofl0r-proxychains-ng-stack-based-buffer-overflowThird Party Advisory
https://github.com/marlinkcyber/advisories/blob/main/advisories/MCSAID-2025-008-proxychains-ng-stack-buffer-overflow-proxy_from_string.mdExploit, Third Party Advisory

Timeline

Published: Dec 18, 2025
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2025-34451?

How severe is CVE-2025-34451?

CVE-2025-34451 has a CVSS score of 6.9/10 (MEDIUM severity). The EPSS model estimates a 0.22% probability of exploitation in the next 30 days.

How do I fix CVE-2025-34451?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2025-34451?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST