CVE-2021-3490

Linux kernel eBPF bitwise ops ALU32 bounds tracking

At a glance

Severity
HIGH 7.8
EPSS
EPSS 27.38 % · percentile 98 (2026-10-27)
State
PUBLISHED
Published
Updated
Assigner
canonical
NVD status
Modified

Description

The eBPF ALU32 bounds tracking for bitwise ops (AND, OR and XOR) in the Linux kernel did not properly update 32-bit bounds, which could be turned into out of bounds reads and writes in the Linux kernel and therefore, arbitrary code execution. This issue was fixed via commit 049c4e13714e ("bpf: Fix alu32 const subreg bound tracking on bitwise operations") (v5.13-rc4) and backported to the stable kernels in v5.12.4, v5.11.21, and v5.10.37. The AND/OR issues were introduced by commit 3f50f132d840 ("bpf: Verifier, do explicit ALU32 bounds tracking") (5.7-rc1) and the XOR variant was introduced by 2921c90d4718 ("bpf:Fix a verifier failure with xor") ( 5.10-rc1).

Scores

VersionScoreVectorScored by
CVSS 3.1HIGH 7.8CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:Hcanonical
CVSS 3.1HIGH 7.8CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:HNVD · security@ubuntu.com (Secondary)
CVSS 3.1HIGH 7.8CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HNVD · nvd@nist.gov (Primary)
CVSS 2.0HIGH 7.2AV:L/AC:L/Au:N/C:C/I:C/A:CNVD · nvd@nist.gov (Primary)

Weaknesses (CWE)

European references

CERT-FR advisories

Affected configurations (NVD CPE)

Affected products

ProductVersions
Linux · Linux kernelaffected trunk < v5.13-rc4 ; affected linux-5.12.y < v5.12.4 ; affected linux-5.11.y < v5.11.21 ; affected linux-5.10.y < v5.10.37 ; affected v5.7-rc1 < 5.7*

References

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD