CVE-2021-33624

Advisory lineage Upstream: 0 Downstream: 24
Modified
Published: 23 Jun 2021, 15:37
Last modified:11 Nov 2025, 15:19

Vulnerability Summary

Overall Risk (default)
medium
29/100
CVSS Score
4.7 MEDIUM
v3.1 (nvd)
EPSS Score
0.47% LOW
0% probability 0.00%
KEV
Not listed
Ransomware
No reports
Public exploits
1 found
Dark Web
Not detected

Timeline

23 Jun 2021, 15:37
Published
Vulnerability first disclosed
11 Nov 2025, 15:19
Last Modified
Vulnerability information updated

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.

CVSS Metrics

  • v3.1•MEDIUM•Score: 4.7CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N
  • v2.0•MEDIUM•Score: 4.7AV:L/AC:M/Au:N/C:C/I:N/A:N

EPSS Trends

Current EPSS score: 0.47%• Percentile: 65%

Techniques & Countermeasures

  • CWE-843•Access of Resource Using Incompatible Type ('Type Confusion')

    The product allocates or initializes a resource such as a pointer, object, or variable using one type, but it later accesses that resource using a type that is incompatible with the original type.

Affected Systems

  • debian•debian_linux

    9.0

  • linux•linux_kernel

    < 5.12.13

References (5)