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Review reviewHigh

CVE-2021-47131

Linux Linux, linux kernel

In the Linux kernel, the following vulnerability has been resolved: net/tls: Fix use-after-free after the TLS device goes down and up When a netdev with active TLS offload goes down, tls_device_down is called to stop the offload and tear down the TLS context. However, the socket stays alive, and it still points to the TLS context, which is now deallocated. If a netdev goes up, while the connection is still active, and the data flow resumes after a number of TCP retransmissions, it will lead to a use-after-free of the TLS context. This commit addresses this bug by keeping the context alive u...

CVSS
7.8
EPSS
0.74%
51.2% percentile
CISA KEV
Not listed
Published
2024.03.16
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability0.74%
Technical severityCVSS 7.8

Vulnerability overview

In the Linux kernel, the following vulnerability has been resolved: net/tls: Fix use-after-free after the TLS device goes down and up When a netdev with active TLS offload goes down, tls_device_down is called to stop the offload and tear down the TLS context. However, the socket stays alive, and it still points to the TLS context, which is now deallocated. If a netdev goes up, while the connection is still active, and the data flow resumes after a number of TCP retransmissions, it will lead to a use-after-free of the TLS context. This commit addresses this bug by keeping the context alive u...

Affected product and versions

Product
Linux Linux, linux kernel
Affected versions
>= e8f69799810c32dd40c6724d829eccc70baad07f < f1d4184f128dede82a59a841658ed40d4e6d3aa2, >= e8f69799810c32dd40c6724d829eccc70baad07f < 0f1e6fe66977a864fe850522316f713d7b926fd9, >= e8f69799810c32dd40c6724d829eccc70baad07f < c55dcdd435aa6c6ad6ccac0a4c636d010ee367a4, >= 4.18, >= 4.18 < 5.10.43, >= 5.11 < 5.12.10, 5.13
Fixed versions
5.10.43, 5.12.10

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that Linux Linux, 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:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE
CWE-416
CVE-2021-47131 — Linux Linux, linux kernel | SECUFOCUS NOW