Red Hat Libuser Race Condition Vulnerability

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• cpe libuser project/libuserversion unspecified
• cpe opensuse/opensuse13.2
• cpe redhat/enterprise linux5.0
• cpe redhat/enterprise linux6.0
• cpe redhat/enterprise linux7.0
• vendor Red Hat Libuserversion unspecified

How to fix CVE-2015-3246

• Recommended remediation

  Apply 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. CISA due date Sep 9, 2026.

• Official advisories

  • CISA KEV · cisa.gov
  • CVE.org · cve.org
  • FIRST EPSS · first.org
  • NIST NVD · nvd.nist.gov
  • VulnCheck KEV · vulncheck.com

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

1. Aug 11, 2015 · Catalog

   Detected

   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.

2. Aug 26, 2026 · CISA KEV

   Known exploited

   Apply 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

3. Sep 9, 2026 · CISA KEV

   Remediation due

   Apply 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

4. Oct 2, 2026 · Catalog

   Updated

   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.

Sources

• CISA KEVConfirmed exploitationCVE-2015-3246

  Red Hat libuser contains a race condition vulnerability that allows authenticated local users to corrupt the /etc/passwd file to cause a denial of service or privilege escalation.

  cisa.gov
• CVE.orgVulnerability recordCVE-2015-3246

  Official CVE identifier

  cve.org
• FIRST EPSSExploitation probabilityCVE-2015-3246

  30-day exploitation probability 8.5%

  first.org
• Exploit DatabasePublic exploit reference37706

  Public archive entry. The exploit body is not stored here.

  exploit-db.com
• Exploit DatabasePublic exploit reference44633

  Public archive entry. The exploit body is not stored here.

  exploit-db.com
• Metasploit ModulesPublic exploit moduleexploit_linux/local/libuser_roothelper_priv_esc

  Public module reference (great). Module source is not copied into this catalog.

  rapid7.com
• NIST NVDVulnerability recordCVE-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

  nvd.nist.gov
• VulnCheck KEVConfirmed exploitationCVE-2015-3246

  Red Hat libuser contains a race condition vulnerability that allows authenticated local users to corrupt the /etc/passwd file to cause a denial of service or privilege escalation.

  vulncheck.com

References

• Broken Link · lists.fedoraproject.org
• Broken Link · lists.fedoraproject.org
• Vendor Advisory · rhn.redhat.com
• Vendor Advisory · rhn.redhat.com
• CISA note · access.redhat.com
• VulnCheck exploitation evidence · blog.talosintelligence.com
• CISA note · nvd.nist.gov
• VulnCheck exploitation evidence · previdian.com
• CISA note · cisa.gov
• CISA note · cisa.gov
• VulnCheck exploitation evidence · cisa.gov
• VulnCheck exploitation evidence · recordedfuture.com

Freshness

Last verified in this catalog Oct 17, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.