CyberSecBulletin
CVE-2022-50413NVD status: Modified

Linux: Use After Free

CVE-2022-50413 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 aebef10affe16228462af680b88751bf137e2856, 40fb87129049ec5876dabf4a4d4aed6642b31f1a 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 0.21% 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 aebef10affe16228462af680b88751bf137e2856 or 40fb87129049ec5876dabf4a4d4aed6642b31f1a, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 6.0.3 or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux81151ce462e533551f3284bfdb8e0f461c9220e6 up to, but not including, aebef10affe16228462af680b88751bf137e2856; 81151ce462e533551f3284bfdb8e0f461c9220e6 up to, but not including, 40fb87129049ec5876dabf4a4d4aed6642b31f1a; 6.0aebef10affe16228462af680b88751bf137e2856, 40fb87129049ec5876dabf4a4d4aed6642b31f1a
LinuxLinux Kernel6.0 up to, but not including, 6.0.36.0.3

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 3.18.8HighCNA
CVSS 3.17.8HighNVD
CVSS 3.17.8HighCISA (ADP)

Official description

In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211: fix use-after-free We've already freed the assoc_data at this point, so need to use another copy of the AP (MLD) address instead.

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: total).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Use After Free vulnerabilities

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