Information disclosure in Linux kernel eBPF

1) Memory leak

EUVDB-ID: #VU67913

Risk: Low

CVSSv3.1: 3.3 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-4159

CWE-ID: CWE-401 - Missing release of memory after effective lifetime

Exploit availability: No

Description

The vulnerability allows a local user to gain access to sensitive information.

The vulnerability exists due memory leak in Linux kernel EBPF verifier when handling internal data structures. A local user with permissions to insert eBPF code to the kernel can force the kernel to leak internal kernel memory details and bypass mitigations, related to exploitation protection.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Linux kernel: All versions

External links

http://access.redhat.com/security/cve/CVE-2021-4159
http://bugzilla.redhat.com/show_bug.cgi?id=2036024
http://security-tracker.debian.org/tracker/CVE-2021-4159
http://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=294f2fc6da27620a506e6c050241655459ccd6bd
http://lists.debian.org/debian-lts-announce/2022/10/msg00000.html

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.