Vulnerability identifier: #VU41049
Vulnerability risk: Medium
CVSSv3.1: 5.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L/E:U/RL:O/RC:C]
CVE-ID:
CWE-ID:
CWE-264
Exploitation vector: Network
Exploit availability: No
Vulnerable software:
Linux kernel
Operating systems & Components /
Operating system
Vendor: Linux Foundation
Description
The vulnerability allows a remote non-authenticated attacker to read and manipulate data.
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.
Mitigation
Install update from vendor's website.
Vulnerable software versions
Linux kernel: 3.0 - 3.0.68, 3.1 - 3.1.10, 3.2, 3.10 - 3.10.29, 3.11 - 3.11.10, 3.12 - 3.12.17, 3.13 - 3.13.11, 3.14 - 3.14.5, 3.15 - 3.15.8, 3.16.0 - 3.16.1, 3.17 - 3.17.2
External links
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
Can this vulnerability be exploited remotely?
Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.
Is there known malware, which exploits this vulnerability?
No. We are not aware of malware exploiting this vulnerability.