Stack-Based Buffer Overflow in Proxychains-ng by Rofl0r
CVE-2025-34451

6.9MEDIUM

Key Information:

Vendor

Rofl0r

Status
Proxychains-ng
Vendor
CVE Published:
18 December 2025

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2025-34451?

Proxychains-ng versions up to and including 4.17 are susceptible to a stack-based buffer overflow within the proxy_from_string() function. This vulnerability occurs when the application processes maliciously crafted proxy configuration entries that include excessively lengthy username or password fields. This flaw can result in memory corruption or application crashes, potentially leading to denial of service. Depending on the specific execution environment and implemented mitigations, attackers may exploit this vulnerability to execute further malicious actions.

Affected Version(s)

proxychains-ng 0 <= 4.17

proxychains-ng commit cc005b7

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2025-34451 - Proof of Concept

References

https://github.com/marlinkcyber/advisories/blob/main/advi...
technical-descriptionexploit
https://github.com/rofl0r/proxychains-ng/issues/606
issue-tracking
https://github.com/httpsgithu/proxychains-ng/commit/cc005b7
patch

CVSS V4

Score:
6.9
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
Availability:
High
Attack Vector:
Local
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

Vlatko Kosturjak with Marlink Cyber
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CVE-2025-34451 : Stack-Based Buffer Overflow in Proxychains-ng by Rofl0r