CVE-2015-3246: Red Hat libuser Race Condition Allows Privilege Escalation
What It Is – A race‑condition flaw in the libuser library on Red Hat Enterprise Linux permits an authenticated local user to corrupt /etc/passwd. The corruption can lead to denial‑of‑service or elevation to root privileges.
Exploitability – The vulnerability is publicly disclosed, has a CVSS 3.0 base score of 7.5 (High), and can be triggered by a local attacker with a valid account; no public exploit code is required.
Affected Products – Red Hat Enterprise Linux (RHEL) 6 and 7 releases that ship the vulnerable libuser package (versions prior to the Red Hat security advisory RHSA‑2015:1245).
Why It Matters for Trust & Control Assurance
- Privilege‑management controls must be demonstrably enforced; a flaw that lets a low‑privilege user become root directly violates the “least‑privilege” objective that underpins many frameworks (e.g., NIST CSF 2.0 Protect).
- Continuous evidence of patch management and configuration baselines is essential to prove due diligence during audits or third‑party assessments.
- An unpatched race condition erodes the audit trail for privileged‑account activity, making it harder to detect or attribute misuse after the fact.
Recommended Actions
- Apply Red Hat’s security update (RHSA‑2015:1245) to upgrade
libuserto the patched version. - Verify the installed package version on all RHEL assets via automated inventory tools.
- Review and tighten local account policies – enforce strong passwords, limit sudo rights, and enable multi‑factor authentication where possible.
- Incorporate the patch‑status check into your continuous control‑monitoring pipeline to generate defensible evidence for auditors.
Source: CISA KEV – CVE‑2015‑3246