CVE-2021-3489 HIGH

CVE-2021-3489: Linux kernel eBPF RINGBUF map oversized allocation

Vendor Linux
Product Linux kernel
Weakness CWE-119
Published June 4, 2021
Last update September 16, 2024

CVSS base score

7.8/10
Attack vector Local
Attack complexity High
Privileges required Low
User interaction None
Confidentiality High
Integrity High

CVSS vector

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H

What the vulnerability does

01Description

The eBPF RINGBUF bpf_ringbuf_reserve() function in the Linux kernel did not check that the allocated size was smaller than the ringbuf size, allowing an attacker to perform out-of-bounds writes within the kernel and therefore, arbitrary code execution. This issue was fixed via commit 4b81ccebaeee ("bpf, ringbuf: Deny reserve of buffers larger than ringbuf") (v5.13-rc4) and backported to the stable kernels in v5.12.4, v5.11.21, and v5.10.37. It was introduced via 457f44363a88 ("bpf: Implement BPF ring buffer and verifier support for it") (v5.8-rc1).

Key dates

02Disclosure timeline

June 4, 2021 CVE published
September 16, 2024 Record updated