ReviewHigh

CVE-2021-38166

linux kernel, fedora

In kernel/bpf/hashtab.c in the Linux kernel through 5.13.8, there is an integer overflow and out-of-bounds write when many elements are placed in a single bucket. NOTE: exploitation might be impractical without the CAP_SYS_ADMIN capability.

CVSS
7.8
EPSS
0.32%
23.9% percentile
CISA KEV
Not listed
Published
2021.08.08
PRIORITY ASSESSMENT

Review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability0.32%
Technical severityCVSS 7.8

Vulnerability overview

In kernel/bpf/hashtab.c in the Linux kernel through 5.13.8, there is an integer overflow and out-of-bounds write when many elements are placed in a single bucket. NOTE: exploitation might be impractical without the CAP_SYS_ADMIN capability.

Affected product and versions

Product
linux kernel, fedora
Affected versions
>= 5.6 < 5.10.60, >= 5.11 < 5.13.12, 33, 34, 11.0
Fixed versions
5.10.60, 5.13.12

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that linux kernel, fedora and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE
CWE-190, CWE-787