CVE-2026-35339

#!/bin/bash # PoC for CVE-2026-35339: uutils coreutils chmod exit code logic error # This script demonstrates the scenario where chmod returns 0 despite errors. mkdir -p /tmp/test_chmod_poc/subdir touch /tmp/test_chmod_poc/protected_file touch /tmp/test_chmod_poc/subdir/normal_file # Simulate a failure on the first file (e.g., by removing write permissions or ownership if possible) # In a real exploit scenario, the attacker would ensure 'protected_file' cannot be modified. # When running 'uutils chmod -R 777 /tmp/test_chmod_poc', if 'normal_file' is processed last, # the command returns exit code 0, hiding the failure on 'protected_file'. echo "Files created. Run 'uutils chmod -R 777 /tmp/test_chmod_poc' and check echo $?" echo "Vulnerable behavior: Exit code is 0 even if protected_file failed."

{"cve": {"id": "CVE-2026-35339", "sourceIdentifier": "[email protected]", "published": "2026-04-22T17:16:35.767", "lastModified": "2026-05-04T20:14:43.883", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "The recursive mode (-R) of the chmod utility in uutils coreutils incorrectly handles exit codes when processing multiple files. The final return value is determined solely by the success or failure of the last file processed. This allows the command to return an exit code of 0 (success) even if errors were encountered on previous files, such as 'Operation not permitted'. Scripts relying on these exit codes may proceed under a false sense of success while sensitive files remain with restrictive or incorrect permissions."}], "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:N/I:H/A:N", "baseScore": 5.5, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "HIGH", "availabilityImpact": "NONE"}, "exploitabilityScore": 1.8, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-253"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:uutils:coreutils:*:*:*:*:*:rust:*:*", "versionEndExcluding": "0.6.0", "matchCriteriaId": "87C33018-2E08-45B0-B69C-7FC224F7F883"}]}]}], "references": [{"url": "https://github.com/uutils/coreutils/pull/9793", "source": "[email protected]", "tags": ["Issue Tracking", "Patch"]}, {"url": "https://github.com/uutils/coreutils/releases/tag/0.6.0", "source": "[email protected]", "tags": ["Release Notes"]}]}}