rofl0r proxychains-ng up to 4.17 src/libproxychains.c proxy_from_string username/password stack-based overflow

Summaryinfo

A vulnerability described as critical has been identified in rofl0r proxychains-ng up to 4.17. This affects the function proxy_from_string in the library src/libproxychains.c. The manipulation of the argument username/password results in stack-based overflow. This vulnerability is reported as CVE-2025-34451. The attack requires a local approach. No exploit exists. A patch should be applied to remediate this issue.

Detailsinfo

A vulnerability classified as problematic has been found in rofl0r proxychains-ng up to 4.17. Affected is the function proxy_from_string in the library src/libproxychains.c. The manipulation of the argument username/password with an unknown input leads to a stack-based overflow vulnerability. CWE is classifying the issue as CWE-121. A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function). This is going to have an impact on availability. CVE summarizes:

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.

The weakness was disclosed by Vlatko Kosturjak as SAID-2025-008. The advisory is available at github.com. This vulnerability is traded as CVE-2025-34451 since 04/15/2025. The exploitability is told to be easy. Local access is required to approach this attack. Technical details are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 279421 (Linux Distros Unpatched Vulnerability : CVE-2025-34451), which helps to determine the existence of the flaw in a target environment.

Applying the patch cc005b7 is able to eliminate this problem.

The vulnerability is also documented in the databases at Tenable (279421) and EUVD (EUVD-2025-204400). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Type

• Firewall Software

Vendor

• rofl0r

Name

• proxychains-ng

Version

• 4.0
• 4.1
• 4.2
• 4.3
• 4.4
• 4.5
• 4.6
• 4.7
• 4.8
• 4.9
• 4.10
• 4.11
• 4.12
• 4.13
• 4.14
• 4.15
• 4.16
• 4.17

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

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Exploitinginfo

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Entryinfo

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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