CVE-2021-33624

4.7 MEDIUM
Published: June 23, 2021 Modified: November 11, 2025

Description

In kernel/bpf/verifier.c in the Linux kernel before 5.12.13, a branch can be mispredicted (e.g., because of type confusion) and consequently an unprivileged BPF program can read arbitrary memory locations via a side-channel attack, aka CID-9183671af6db.

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/06/21/1
Source: cve@mitre.org
Exploit Mailing List Third Party Advisory
https://lists.debian.org/debian-lts-announce/2021/10/msg00010.html
Source: cve@mitre.org
Issue Tracking Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/06/21/1
Source: af854a3a-2127-422b-91ae-364da2661108
Exploit Mailing List Third Party Advisory
https://github.com/torvalds/linux/commit/9183671af6dbf60a1219371d4ed73e23f43b49db
Source: af854a3a-2127-422b-91ae-364da2661108
Patch Third Party Advisory
https://lists.debian.org/debian-lts-announce/2021/10/msg00010.html
Source: af854a3a-2127-422b-91ae-364da2661108
Issue Tracking Third Party Advisory
https://www.usenix.org/conference/usenixsecurity21/presentation/kirzner
Source: af854a3a-2127-422b-91ae-364da2661108
Third Party Advisory

9 reference(s) from NVD

Quick Stats

CVSS v3 Score
4.7 / 10.0
EPSS (Exploit Probability)
0.5%
64th percentile
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)

Affected Vendors

linux debian