#VU1039 Privilege escalation in Linux kernel - CVE-2016-5195

Vulnerability identifier: #VU1039

Vulnerability risk: Medium

CVSSv4.0: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:A/U:Green]

CVE-ID: CVE-2016-5195

CWE-ID: CWE-362

Exploitation vector: Local

Exploit availability: Yes

Vulnerable software:
Linux kernel
Operating systems & Components / Operating system

Vendor: Linux Foundation

Description
The vulnerability allows a  local user to obtain elevated privileges on the target system.
The weakness is due to race condition in the kernel memory subsystem in the management of copy-on-write operations on read-only memory mappings that lets attackers to overwrite kernel memory and gain kernel-level privileges.
Successful exploitation of the vulnerability results in gaining of root privileges on the vulnerable system.

Note: the vulnerability was being actively exploited.

Mitigation
Update to version 4.9-rc2.
https://cdn.kernel.org/pub/linux/kernel/v4.x/testing/linux-4.9-rc2.tar.xz

Vulnerable software versions

Linux kernel: 2.6.0 - 2.6.36 rc3, 3.0 - 3.0.68, 3.1 - 3.19, 3.2 - 3.2.81-1, 3.3 - 3.3.8, 3.4 - 3.4.32, 3.5.1 - 3.5.5, 3.8, 3.9, 4.0.1 - 4.0.9, 4.1 - 4.1.38, 4.2.0 - 4.2.8, 4.3 - 4.3.6, 4.4.0 - 4.4.52, 4.5.0 - 4.5.7, 4.6 rc1 - 4.6.7, 4.7.0 - 4.7.10, 4.8.0 - 4.8.3

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External links
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=19be0eaffa3ac7d8eb6784ad9...

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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?

Yes. This vulnerability is being exploited in the wild.