#VU55260 Use-after-free in Linux kernel - CVE-2019-20934

Vulnerability identifier: #VU55260

Vulnerability risk: Low

CVSSv4.0: 2 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2019-20934

CWE-ID: CWE-416

Exploitation vector: Local

Exploit availability: No

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

Vendor: Linux Foundation

Description

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

The vulnerability exists due to a use-after-free error in Linux fair scheduler within the show_numa_stats() function, caused by improperly freed NUMA fault statistics. A local user can trigger a use-after-free error and escalate privileges on the system.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Linux kernel: before 5.2.6, 5.2.6

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External links
https://bugs.chromium.org/p/project-zero/issues/detail?id=1913
https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.2.6
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=16d51a590a8ce3befb1308e0e7ab77f3b661af33

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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.