CVE-2014-8989

Severity: medium (CVSS 4.6 v2.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2014-11-30 · updated 2026-06-17
Weakness: CWE-264

Description

The Linux kernel through 3.17.4 does not properly restrict dropping of supplemental group memberships in certain namespace scenarios, which allows local users to bypass intended file permissions by leveraging a POSIX ACL containing an entry for the group category that is more restrictive than the entry for the other category, aka a "negative groups" issue, related to kernel/groups.c, kernel/uid16.c, and kernel/user_namespace.c.

Affected products

Linux kernel: through 3.17.3; 3.0-rc1, 3.0-rc2, 3.0-rc3, 3.0-rc4, 3.0-rc5, 3.0-rc6 (+187)

References

http://lists.fedoraproject.org/pipermail/package-announce/2015-January/147864.html
http://lists.fedoraproject.org/pipermail/package-announce/2015-January/147973.html
http://thread.gmane.org/gmane.linux.man/7385/
http://www.mandriva.com/security/advisories?name=MDVSA-2015:058
http://www.openwall.com/lists/oss-security/2014/11/20/4
http://www.securityfocus.com/bid/71154
http://www.ubuntu.com/usn/USN-2515-1
http://www.ubuntu.com/usn/USN-2516-1
http://www.ubuntu.com/usn/USN-2517-1
http://www.ubuntu.com/usn/USN-2518-1
http://lists.fedoraproject.org/pipermail/package-announce/2015-January/147864.html
http://lists.fedoraproject.org/pipermail/package-announce/2015-January/147973.html

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