Cyber Resilience

CVE-2021-33624

MediumPublic PoC

Published: 23 June 2021

Published
23 June 2021
Modified
11 November 2025
KEV Added
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Patch
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CVSS Score v3.1 4.7 CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N
EPSS Score 0.0047 65.2th percentile
Risk Priority 10 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-33624 is a medium-severity Type Confusion (CWE-843) vulnerability in Linux Linux Kernel. Its CVSS base score is 4.7 (Medium).

Operationally, ranked in the top 34.8% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability details

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.

CWE(s)
CWE-843

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

linux
linux kernel
≤ 5.12.13
debian
debian linux
9.0

Mitigating Controls

No mitigating controls mapped yet. The per-CVE control annotator has not reached this CVE.

References