CVE-2021-34866

Published: 25 January 2022

This vulnerability allows local attackers to escalate privileges on affected installations of Linux Kernel 5.14-rc3. An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability. The specific flaw exists within the handling of eBPF programs. The issue results from the lack of proper validation of user-supplied eBPF programs, which can result in a type confusion condition. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of the kernel. Was ZDI-CAN-14689.

From the Ubuntu security team

Ryota Shiga discovered that the eBPF implementation in the Linux kernel did not enforce that ringbuf helpers were not used with different BPF map types. A local attacker could use this to possibly execute arbitrary code.

Priority

Medium

CVSS 3 base score: 7.8

Status

References

• https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-34866
• https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=5b029a32cfe4600f5e10e36b41778506b90fd4de
• NVD
• Launchpad
• Debian