imPC@ndo IT

Tracker / CVE-2021-3444

CVE-2021-3444

High 7.8

The bpf verifier in the Linux kernel did not properly handle mod32 destination register truncation when the source register was known to be 0. A local attacker with the ability to load bpf programs could use this gain out-of-bounds reads in kernel memory leading to information disclosure (kernel memory), and possibly out-of-bounds writes that could potentially lead to code execution. This issue was addressed in the upstream kernel in commit 9b00f1b78809 ("bpf: Fix truncation handling for mod32 dst reg wrt zero") and in Linux stable kernels 5.11.2, 5.10.19, and 5.4.101.

Affected products and versions

canonical ubuntu_linux
debian debian_linux
linux linux_kernel · … → 5.4.101
linux linux_kernel · 5.11 → 5.11.2
linux linux_kernel · 5.5.0 → 5.10.19

Analysis

This page is not indexable yet.Until it carries original analysis — what it actually exposes, how to check in two minutes whether a system was touched, what to do if it was — the page stays noindex. The database decides that, not the template.

References