Vulnerability identifier: #VU63649

Vulnerability risk: Low

CVSSv3.1: 7 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:P/RL:O/RC:C]

CVE-ID: CVE-2016-2853

CWE-ID: CWE-269

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 escalate privileges.

The vulnerability exists due to improper restriction of the mount namespace. A local user can mount an aufs filesystem on top of a FUSE filesystem, and then execute a crafted setuid program to escalate privileges.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Linux kernel:

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External links
http://www.halfdog.net/Security/2016/AufsPrivilegeEscalationInUserNamespaces/
http://www.openwall.com/lists/oss-security/2016/02/24/9
http://sourceforge.net/p/aufs/mailman/message/34864744/
http://www.securityfocus.com/bid/96839
http://www.openwall.com/lists/oss-security/2021/10/18/1

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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?

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