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Review reviewCritical

CVE-2021-47232

Linux Linux, linux_kernel, linux kernel

In the Linux kernel, the following vulnerability has been resolved: can: j1939: fix Use-after-Free, hold skb ref while in use This patch fixes a Use-after-Free found by the syzbot. The problem is that a skb is taken from the per-session skb queue, without incrementing the ref count. This leads to a Use-after-Free if the skb is taken concurrently from the session queue due to a CTS.

CVSS
9.8
EPSS
-
- percentile
CISA KEV
Not listed
Published
2024.05.22
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability-
Technical severityCVSS 9.8

Vulnerability overview

In the Linux kernel, the following vulnerability has been resolved: can: j1939: fix Use-after-Free, hold skb ref while in use This patch fixes a Use-after-Free found by the syzbot. The problem is that a skb is taken from the per-session skb queue, without incrementing the ref count. This leads to a Use-after-Free if the skb is taken concurrently from the session queue due to a CTS.

Affected product and versions

Product
Linux Linux, linux_kernel, linux kernel
Affected versions
>= 9d71dd0c70099914fcd063135da3c580865e924c < 22cba878abf646cd3a02ee7c8c2cef7afe66a256, >= 9d71dd0c70099914fcd063135da3c580865e924c < 509ab6bfdd0c76daebbad0f0af07da712116de22, >= 9d71dd0c70099914fcd063135da3c580865e924c < 1071065eeb33d32b7d98c2ce7591881ae7381705, >= 9d71dd0c70099914fcd063135da3c580865e924c < 2030043e616cab40f510299f09b636285e0a3678, >= 5.4, >= 9d71dd0c7009 < 22cba878abf6, >= 9d71dd0c7009 < 509ab6bfdd0c, >= 9d71dd0c7009 < 1071065eeb33, >= 9d71dd0c7009 < 2030043e616c, >= 5.4 < 5.4.128, >= 5.5 < 5.10.46, >= 5.11 < 5.12.13, 5.13
Fixed versions
5.4.128, 5.10.46, 5.12.13

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that Linux Linux, linux_kernel, linux kernel 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:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CWE
CWE-416