CVE-2017-5551 Information

Description

The simple_set_acl function in fs/posix_acl.c in the Linux kernel before 4.9.6 preserves the setgid bit during a setxattr call involving a tmpfs filesystem which allows local users to gain group privileges by leveraging the existence of a setgid program with restrictions on execute permissions. NOTE: this vulnerability exists because of an incomplete fix for CVE-2016-7097.

CVSS Vector

CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N

Reference

http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=497de07d89c1410d76a15bec2bb41f24a2a89f31 http://www.debian.org/security/2017/dsa-3791 http://www.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.9.6 http://www.openwall.com/lists/oss-security/2017/01/21/3 http://www.securityfocus.com/bid/95717 http://www.securitytracker.com/id/1038053 https://bugzilla.redhat.com/show_bug.cgi?id=1416126 https://github.com/torvalds/linux/commit/497de07d89c1410d76a15bec2bb41f24a2a89f31

Attack Complexity

LOW

Privileges Required

LOW

User Interaction Required

LOW

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

LOW

Availability Impact

LOW

Base Score

NONE

Base Severity

4.4