Privilege escalation in Linux kernel

1) Use-after-free

EUVDB-ID: #VU14817

Risk: Low

CVSSv3.1: 6.8 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2018-17182

CWE-ID: CWE-416 - Use After Free

Exploit availability: No

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a use-after-free error in vmacache_flush_all() function in mm/vmacache.c file. A local user can trigger the use-after-free error via certain thread creation, map, unmap, invalidation, and dereference operations and execute arbitrary code on the system with elevated privileges.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Linux kernel: 4.18 - 4.18.8

External links

http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=7a9cdebdcc17e426fb5287e4a82db1dfe86339b2
http://github.com/torvalds/linux/commit/7a9cdebdcc17e426fb5287e4a82db1dfe86339b2
http://www.openwall.com/lists/oss-security/2018/09/18/4

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.