#VU63836 Memory leak in Linux kernel - CVE-2021-4002

Vulnerability identifier: #VU63836

Vulnerability risk: Low

CVSSv4.0: 1.1 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2021-4002

CWE-ID: CWE-401

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 gain access to sensitive information.

The vulnerability exists due memory leak in the Linux kernel's hugetlbfs memory usage. A local user can force the application to leak memory and gain access to sensitive information.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Linux kernel: before 5.16, 5.16

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External links
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=13e4ad2ce8df6e058ef482a31fdd81c725b0f7ea
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=a4a118f2eead1d6c49e00765de89878288d4b890
https://bugzilla.redhat.com/show_bug.cgi?id=2025726
https://www.openwall.com/lists/oss-security/2021/11/25/1
https://lists.debian.org/debian-lts-announce/2022/03/msg00012.html
https://lists.debian.org/debian-lts-announce/2022/03/msg00011.html
https://www.debian.org/security/2022/dsa-5096

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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.