ReviewHigh

CVE-2021-3501

Linux kernel, linux kernel, enterprise linux

A flaw was found in the Linux kernel in versions before 5.12. The value of internal.ndata, in the KVM API, is mapped to an array index, which can be updated by a user process at anytime which could lead to an out-of-bounds write. The highest threat from this vulnerability is to data integrity and system availability.

CVSS
7.1
EPSS
0.37%
30.5% percentile
CISA KEV
Not listed
Published
2021.05.06
PRIORITY ASSESSMENT

Review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability0.37%
Technical severityCVSS 7.1

Vulnerability overview

A flaw was found in the Linux kernel in versions before 5.12. The value of internal.ndata, in the KVM API, is mapped to an array index, which can be updated by a user process at anytime which could lead to an out-of-bounds write. The highest threat from this vulnerability is to data integrity and system availability.

Affected product and versions

Product
Linux kernel, linux kernel, enterprise linux
Affected versions
>= 5.9 < 5.10.32, >= 5.11 < 5.11.16, < 5.12, 8.0, 8, 8.4, 33, 4.0
Fixed versions
5.12

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that Linux kernel, linux kernel, enterprise linux 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:N/I:H/A:H
CWE
CWE-787