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CVE-2024-26928NVD status: Analyzed

Linux: Use After Free

CVE-2024-26928 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 8f8718afd446cd4ea3b62bacc3eec09f8aae85ee, a140224bcf87eb98a87b67ff4c6826c57e47b704, 229042314602db62559ecacba127067c22ee7b88 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 0.28% 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 8f8718afd446cd4ea3b62bacc3eec09f8aae85ee or a140224bcf87eb98a87b67ff4c6826c57e47b704 or 229042314602db62559ecacba127067c22ee7b88 or a65f2b56334ba4dc30bd5ee9ce5b2691b973344d, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 5.10.237 or 5.15.180 or 6.1.85 or 6.6.26, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinuxdfe33f9abc08997e56f9bdf14fe9ac7ac0e14075 up to, but not including, 8f8718afd446cd4ea3b62bacc3eec09f8aae85ee; dfe33f9abc08997e56f9bdf14fe9ac7ac0e14075 up to, but not including, a140224bcf87eb98a87b67ff4c6826c57e47b704; dfe33f9abc08997e56f9bdf14fe9ac7ac0e14075 up to, but not including, 229042314602db62559ecacba127067c22ee7b88; dfe33f9abc08997e56f9bdf14fe9ac7ac0e14075 up to, but not including, a65f2b56334ba4dc30bd5ee9ce5b2691b973344d; dfe33f9abc08997e56f9bdf14fe9ac7ac0e14075 up to, but not including, 3402faf78b2516b0af1259baff50cc8453ef0bd1; dfe33f9abc08997e56f9bdf14fe9ac7ac0e14075 up to, but not including, ca545b7f0823f19db0f1148d59bc5e1a56634502; 4.208f8718afd446cd4ea3b62bacc3eec09f8aae85ee, a140224bcf87eb98a87b67ff4c6826c57e47b704, 229042314602db62559ecacba127067c22ee7b88, a65f2b56334ba4dc30bd5ee9ce5b2691b973344d, 3402faf78b2516b0af1259baff50cc8453ef0bd1, ca545b7f0823f19db0f1148d59bc5e1a56634502
DebianDebian Linux11.0Not stated
LinuxLinux Kernel4.20 up to, but not including, 5.10.237; 5.11 up to, but not including, 5.15.180; 5.16 up to, but not including, 6.1.85; 6.2 up to, but not including, 6.6.26; 6.7 up to, but not including, 6.8.5; 6.95.10.237, 5.15.180, 6.1.85, 6.6.26, 6.8.5

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.

Official description

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix potential UAF in cifs_debug_files_proc_show() Skip sessions that are being teared down (status == SES_EXITING) to avoid UAF.

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

Third-party and government advisories

Recent Use After Free vulnerabilities

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