What is CVE-2021-33624?

CVE-2021-33624 is a Medium severity Linux kernel vulnerability with a CVSS score of 4.7 out of 10. CVE-2021-33624 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2021-33624?

CVE-2021-33624 has a CVSS score of 4.7 out of 10, rated Medium severity. The vector string is CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N.

Is there a patch available for CVE-2021-33624?

No patch is currently available for CVE-2021-33624. Monitor the NIST NVD and your Linux distribution's security advisories for updates.

Is CVE-2021-33624 actively exploited?

CVE-2021-33624 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2021-33624

Medium

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.

Package Linux Kernel

Published 2021-06-23

Last modified 2025-11-11

CVSS version 3.1

Patch available

Awaiting data

CVSS 3.1 score

4.7

out of 10

Medium

Attack Vector

Local

Attack Complexity

High

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

None

Availability

None

Vector string

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

Weakness type

CWE-843

CVE-2021-33624 is classified as CWE-843

See CWE-843 on MITRE CWE for full details on this weakness type.

References

The following references provide additional information about CVE-2021-33624 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

Openwall
http://www.openwall.com/lists/oss-security/2021/06/21/1

Exploit Mailing List Third Party Advisory
GitHub
https://github.com/benschlueter/CVE-2021-33624
Debian Security
https://lists.debian.org/debian-lts-announce/2021/10/msg00010.html

Issue Tracking Third Party Advisory
Usenix
https://www.usenix.org/conference/usenixsecurity21/presentation/kirzner

Third Party Advisory
Kernel patch commit
https://github.com/torvalds/linux/commit/9183671af6dbf60a1219371d4ed73e23f43b49db
Patch

Details

CVE ID CVE-2021-33624

Severity Medium

CVSS score 4.7 / 10

CVSS version 3.1

Published 2021-06-23

Modified 2025-11-11

KEV No

Patch Awaiting data

Package linux

Frequently asked questions

What is CVE-2021-33624?

CVE-2021-33624 is a Medium severity Linux kernel vulnerability with a CVSS score of 4.7 out of 10 . CVE-2021-33624 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2021-33624?

CVE-2021-33624 has a CVSS score of 4.7 out of 10, rated Medium severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N.
Is there a patch available for CVE-2021-33624?

No patch is currently available for CVE-2021-33624. Monitor the NIST NVD and your Linux distribution's security advisories for updates.
Is CVE-2021-33624 actively exploited?

No — CVE-2021-33624 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.