CVE-2021-33624

low-risk
Published 2021-06-23

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.

Do I need to act?

-
0.47% chance of exploitation
EPSS score — low exploit probability
-
Not on CISA KEV list
No confirmed active exploitation reported to CISA
?
Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
4
CVSS 4.7/10 Medium
LOCAL / HIGH complexity

Affected Products (2)

Affected Vendors

Debian Linux

References (9)

Exploit http://www.openwall.com/lists/oss-security/2021/06/21/1
https://github.com/benschlueter/CVE-2021-33624
Patch https://github.com/torvalds/linux/commit/9183671af6dbf60a1219371d4ed73e23f43b49d...
Issue Tracking https://lists.debian.org/debian-lts-announce/2021/10/msg00010.html
Third Party Advisory https://www.usenix.org/conference/usenixsecurity21/presentation/kirzner
Exploit http://www.openwall.com/lists/oss-security/2021/06/21/1
Patch https://github.com/torvalds/linux/commit/9183671af6dbf60a1219371d4ed73e23f43b49d...
Issue Tracking https://lists.debian.org/debian-lts-announce/2021/10/msg00010.html
Third Party Advisory https://www.usenix.org/conference/usenixsecurity21/presentation/kirzner
21
/ 100
low-risk
Severity 12/34 · Low
Exploitability 2/34 · Minimal
Exposure 7/34 · Low