How severe is CVE-2025-34451?

CVE-2025-34451 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2025-34451 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (12th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-34451?

CVE-2025-34451 affects Proxychains-ng Project Proxychains-ng. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2025-34451?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2025-34451 have an EU (EUVD) identifier?

Yes. CVE-2025-34451 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-204400.

When was CVE-2025-34451 published?

CVE-2025-34451 was published on 2025-12-18 and last updated on 2026-06-17.

CVE-2025-34451

CVE-2025-34451 is a high-severity vulnerability in Proxychains-ng Project Proxychains-ng with a CVSS 3.x base score of 7.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-787.

Key facts

Severity: High (CVSS 3.x base score 7.8)
CVSS v4: 6.9
EPSS exploit prediction: 0% (12th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-204400
Weakness: CWE-787
Affected product: Proxychains-ng Project Proxychains-ng
Published: 2025-12-18
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2025-34451?: 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.
How severe is CVE-2025-34451?: CVE-2025-34451 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2025-34451 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (12th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-34451?: CVE-2025-34451 affects Proxychains-ng Project Proxychains-ng. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2025-34451?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2025-34451 have an EU (EUVD) identifier?: Yes. CVE-2025-34451 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-204400.
When was CVE-2025-34451 published?: CVE-2025-34451 was published on 2025-12-18 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:proxychains-ng_project:proxychains-ng:*:*:*:*:*:*:*:*

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