CVE-2015-3246
libuser before 0.56.13-8 and 0.60 before 0.60-7, as used in the userhelper program in the usermode package, directly modifies /etc/passwd, which allows local users to cause a denial of service (inconsistent file state) by causing an error during the modification. NOTE: this issue can be combined with CVE-2015-3245 to gain privileges.
do firstApply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
Can a WAF block it? No. The attack needs local access to the machine, so a WAF is not on its path.
Also consider: patch
Based on the attack vector (local or physical access). We check Cloudflare, AWS, Google Cloud Armor and Azure; for Akamai, Imperva, Fastly, F5, ask your vendor.
Is CVE-2015-3246 being exploited?
Yes. CVE-2015-3246 appears in CISA's Known Exploited Vulnerabilities catalog, which means exploitation in the wild has been confirmed and reported. Treat it as active rather than theoretical, and patch it ahead of higher-scoring vulnerabilities that carry no exploitation evidence.
How severe is CVE-2015-3246?
CVE-2015-3246 is rated High with a CVSS score of 7.4. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2015-3246?
Yes. A fix has been recorded for CVE-2015-3246. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2015-3246 affect?
CVE-2015-3246 affects redhat:enterprise_linux, opensuse:opensuse, libuser_project:libuser. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
public exploits
Public exploit code: 3 on Exploit-DB · 1 Metasploit module · 1 GitHub proof of concept
- Libuser - 'roothelper' Local Privilege Escalation (Metasploit) · local · 16 May 2018 · verified
- Libuser - 'roothelper' Local Privilege Escalation (Metasploit) · local · 16 May 2018 · verified
- Libuser Library - Multiple Vulnerabilities · dos · 27 Jul 2015 · verified
- exploit/linux/local/libuser_roothelper_priv_esc · exploit · great
- HORKimhab/CVE-2015-3246 · 0 ★
Listed so you can judge urgency, not as a recommendation to run anything. GitHub “proofs of concept” are unvetted: some are fake or carry malware. Exploit-DB marks the entries its staff verified.
cisa ssvc
- exploitation
- active
- automatable
- no
- technical impact
- total
Assessed by CISA 27 Aug 2026 (SSVC 2.0.3).
timeline
- 27 Jul 2015First public exploit or proof of concept
- 11 Aug 2015Published · 16 days later
- 26 Aug 2026Added to CISA KEV (exploited in the wild) · 4,032 days (about 11 years) later
- 27 Aug 2026CISA SSVC assessment: exploitation active · 1 day later
- 9 Sept 2026CISA remediation due date (US federal agencies) · 13 days later
- 1 Oct 2026CVE record last updated · 23 days later
- 2 Nov 2026Analysed by vulneraibility.com · 32 days later
- Advisorylists.fedoraproject.org /pipermail/package-announce/2015-July/162947.html
- Advisoryrhn.redhat.com /errata/RHSA-2015-1482.html
- Advisorylists.fedoraproject.org /pipermail/package-announce/2015-August/163044.html
- Advisorylists.opensuse.org /opensuse-security-announce/2015-08/msg00000.html
- Advisoryrhn.redhat.com /errata/RHSA-2015-1483.html
- Advisoryblog.talosintelligence.com /uat-10147-chinese-speaking-adversary-integrates-agentic-ai-into-post-compromise
- Exploitexploit-db.com /exploits/44633/
- Linksecurityfocus.com /bid/76022
Show 4 more
- Linkaccess.redhat.com /articles/1537873
- Linkqualys.com /2015/07/23/cve-2015-3245-cve-2015-3246/cve-2015-3245-cve-2015-3246.txt
- Linksecuritytracker.com /id/1033040
- Linkcisa.gov /known-exploited-vulnerabilities-catalog?field_cve=CVE-2015-3246
sources
- CVE List (CVE.org): description, affected versions, references; CVE Terms of Use
- NVD: CVSS and CPE data
- CISA KEV catalog: exploitation, date added, due date
- CISA Vulnrichment (ADP): SSVC decision points
- FIRST EPSS: exploit probability and percentile
- Exploit-DB: published exploits
- Metasploit Framework: exploit and scanner modules
- PoC-in-GitHub: GitHub repositories that claim a proof of concept
- Summary, impact and triage tags: written by our AI analysis pipeline from the sources above. Check them against the sources.