ReviewHigh

CVE-2021-44733

linux kernel, enterprise linux

A use-after-free exists in drivers/tee/tee_shm.c in the TEE subsystem in the Linux kernel through 5.15.11. This occurs because of a race condition in tee_shm_get_from_id during an attempt to free a shared memory object.

CVSS
7
EPSS
0.70%
50.8% percentile
CISA KEV
Not listed
Published
2021.12.23
PRIORITY ASSESSMENT

Review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability0.70%
Technical severityCVSS 7

Vulnerability overview

A use-after-free exists in drivers/tee/tee_shm.c in the TEE subsystem in the Linux kernel through 5.15.11. This occurs because of a race condition in tee_shm_get_from_id during an attempt to free a shared memory object.

Affected product and versions

Product
linux kernel, enterprise linux
Affected versions
>= 4.12 < 4.14.261, >= 4.15 < 4.19.224, >= 4.20 < 5.4.170, >= 5.5 < 5.10.89, >= 5.11 < 5.15.12, 8.0, 35, 9.0, 10.0, 11.0
Fixed versions
4.14.261, 4.19.224, 5.4.170, 5.10.89, 5.15.12

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that 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:H/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE
CWE-362