#VU64881 Type Confusion in Linux kernel - CVE-2021-33624

Vulnerability identifier: #VU64881

Vulnerability risk: Low

CVSSv4.0: 1.9 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:P/U:Clear]

CVE-ID: CVE-2021-33624

CWE-ID: CWE-843

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 gain access to sensitive information.

The vulnerability exists due to a type confusion error within kernel/bpf/verifier.c in the Linux kernel. A an unprivileged BPF program can read arbitrary memory locations via a side-channel attack.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Linux kernel: before 5.12.13, 5.12.13

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External links
https://source.android.com/security/bulletin/pixel/2022-03-01
https://android.googlesource.com/kernel/common/+/5fc6ed1831ca5

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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.