#VU56241 Command Injection in Linux kernel - CVE-2021-29154

Vulnerability identifier: #VU56241

Vulnerability risk: Low

CVSSv4.0: 5.9 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2021-29154

CWE-ID: CWE-77

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 incorrect computation of branch displacements within the BPF JIT compilers in the Linux kernel in arch/x86/net/bpf_jit_comp.c and arch/x86/net/bpf_jit_comp32.c. A local user can inject and execute arbitrary commands with elevated privileges.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Linux kernel: before 5.11.13, 5.11.13

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External links
https://www.openwall.com/lists/oss-security/2021/04/08/1
https://news.ycombinator.com/item?id=26757760
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/W5YFGIIF24475A2LNW3UWHW2SNCS3G7M/
https://packetstormsecurity.com/files/162434/Kernel-Live-Patch-Security-Notice-LSN-0076-1.html
https://security.netapp.com/advisory/ntap-20210604-0006/
https://lists.debian.org/debian-lts-announce/2021/06/msg00019.html
https://lists.debian.org/debian-lts-announce/2021/06/msg00020.html

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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.