CyberSecBulletin
CVE-2024-46831NVD status: Modified

Linux: Use After Free

Published Updated By the CyberSecBulletin desk

CVE-2024-46831 is a high-severity use after free vulnerability in Linux, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions b0804c286ccfcf5f5c004d5bf8a54c0508b5e86b, f7fe95f40c85311c98913fe6ae2c56adb7f767a7, a3c1e45156ad39f225cd7ddae0f81230a3b1e657 as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.24% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Linux to b0804c286ccfcf5f5c004d5bf8a54c0508b5e86b or f7fe95f40c85311c98913fe6ae2c56adb7f767a7 or a3c1e45156ad39f225cd7ddae0f81230a3b1e657, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 6.6.51 or 6.10.10, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinuxc956b9b318d9036701c471dd458f9ed31defc629 up to, but not including, b0804c286ccfcf5f5c004d5bf8a54c0508b5e86b; c956b9b318d9036701c471dd458f9ed31defc629 up to, but not including, f7fe95f40c85311c98913fe6ae2c56adb7f767a7; c956b9b318d9036701c471dd458f9ed31defc629 up to, but not including, a3c1e45156ad39f225cd7ddae0f81230a3b1e657; 6.2b0804c286ccfcf5f5c004d5bf8a54c0508b5e86b, f7fe95f40c85311c98913fe6ae2c56adb7f767a7, a3c1e45156ad39f225cd7ddae0f81230a3b1e657
LinuxLinux Kernel6.2 up to, but not including, 6.6.51; 6.7 up to, but not including, 6.10.10; 6.116.6.51, 6.10.10

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.18.4HighCNA
CVSS 3.17.8HighNVD

Official description

In the Linux kernel, the following vulnerability has been resolved: net: microchip: vcap: Fix use-after-free error in kunit test This is a clear use-after-free error. We remove it, and rely on checking the return code of vcap_del_rule.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Use After Free

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.

How developers prevent this class of flaw

  • Choose a language that provides automatic memory management.
  • When freeing pointers, be sure to set them to NULL once they are freed. However, the utilization of multiple or complex data structures may lower the usefulness of this strategy.

More Use After Free vulnerabilities (CWE-416)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Use After Free vulnerabilities

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