Permissions, Privileges, and Access Controls in Linux kernel

1) Permissions, Privileges, and Access Controls

EUVDB-ID: #VU41395

Risk: Low

CVSSv4.0: 6.2 [CVSS:4.0/AV:L/AC:L/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/U:Clear]

CVE-ID: CVE-2014-5207

CWE-ID: CWE-264 - Permissions, Privileges, and Access Controls

Exploit availability: Yes

Description

The vulnerability allows a local #AU# to execute arbitrary code.

fs/namespace.c in the Linux kernel through 3.16.1 does not properly restrict clearing MNT_NODEV, MNT_NOSUID, and MNT_NOEXEC and changing MNT_ATIME_MASK during a remount of a bind mount, which allows local users to gain privileges, interfere with backups and auditing on systems that had atime enabled, or cause a denial of service (excessive filesystem updating) on systems that had atime disabled via a "mount -o remount" command within a user namespace.

Mitigation

Install update from vendor's website.

Vulnerable software versions

Linux kernel: 3.0 - 3.16.0

CPE2.3

• cpe:2.3:o:linux_foundation:linux_kernel:3.0:*:*:*:*:*:*:*
• cpe:2.3:o:linux_foundation:linux_kernel:3.0.1:*:*:*:*:*:*:*
• cpe:2.3:o:linux_foundation:linux_kernel:3.0.2:*:*:*:*:*:*:*
• cpe:2.3:o:linux_foundation:linux_kernel:3.0.3:*:*:*:*:*:*:*
• cpe:2.3:o:linux_foundation:linux_kernel:3.0.4:*:*:*:*:*:*:*
• cpe:2.3:o:linux_foundation:linux_kernel:3.0.5:*:*:*:*:*:*:*
• cpe:2.3:o:linux_foundation:linux_kernel:3.0.6:*:*:*:*:*:*:*
• cpe:2.3:o:linux_foundation:linux_kernel:3.0.7:*:*:*:*:*:*:*
• cpe:2.3:o:linux_foundation:linux_kernel:3.0.8:*:*:*:*:*:*:*
• cpe:2.3:o:linux_foundation:linux_kernel:3.0.9:*:*:*:*:*:*:*

External links

https://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=9566d6742852c527bf5af38af5cbb878dad75705
https://osvdb.org/show/osvdb/110055
https://packetstormsecurity.com/files/128595/Linux-Kernel-3.16.1-FUSE-Privilege-Escalation.html
https://seclists.org/oss-sec/2014/q3/352
https://www.exploit-db.com/exploits/34923
https://www.openwall.com/lists/oss-security/2014/08/13/4
https://www.securityfocus.com/bid/69216
https://www.ubuntu.com/usn/USN-2317-1
https://www.ubuntu.com/usn/USN-2318-1
https://bugzilla.redhat.com/show_bug.cgi?id=1129662
https://exchange.xforce.ibmcloud.com/vulnerabilities/95266
https://github.com/torvalds/linux/commit/9566d6742852c527bf5af38af5cbb878dad75705

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.