Linux: Use After Free
CVE-2024-35866 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 d798fd98e3563027c5162259ead517057d6fa794, f4a60d360d9114b5085701a3702a0102b0d6d846, 10e17ca4000ec34737bde002a13435c38ace2682 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.
High severity with no evidence of exploitation so far.
What to do
- Update Linux to d798fd98e3563027c5162259ead517057d6fa794 or f4a60d360d9114b5085701a3702a0102b0d6d846 or 10e17ca4000ec34737bde002a13435c38ace2682 or 3103163ccd3be4adcfa37e15608fb497be044113, whichever matches your release line, or a later version.
- Update Linux Kernel to 5.15.181 or 6.1.132 or 6.6.26 or 6.8.5, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 1bb56810677f26b78d57a3038054943efd334a1c up to, but not including, d798fd98e3563027c5162259ead517057d6fa794; 1bb56810677f26b78d57a3038054943efd334a1c up to, but not including, f4a60d360d9114b5085701a3702a0102b0d6d846; 1bb56810677f26b78d57a3038054943efd334a1c up to, but not including, 10e17ca4000ec34737bde002a13435c38ace2682; 1bb56810677f26b78d57a3038054943efd334a1c up to, but not including, 3103163ccd3be4adcfa37e15608fb497be044113; 1bb56810677f26b78d57a3038054943efd334a1c up to, but not including, 58acd1f497162e7d282077f816faa519487be045; 5.13 | d798fd98e3563027c5162259ead517057d6fa794, f4a60d360d9114b5085701a3702a0102b0d6d846, 10e17ca4000ec34737bde002a13435c38ace2682, 3103163ccd3be4adcfa37e15608fb497be044113, 58acd1f497162e7d282077f816faa519487be045 |
| Debian | Debian Linux | 11.0 | Not stated |
| Linux | Linux Kernel | 5.13 up to, but not including, 5.15.181; 5.16 up to, but not including, 6.1.132; 6.2 up to, but not including, 6.6.26; 6.7 up to, but not including, 6.8.5; 6.9 | 5.15.181, 6.1.132, 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_dump_full_key() 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.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- git.kernel.org/stable/c/10e17ca4000ec34737bde002a13435c38ace2682
- git.kernel.org/stable/c/3103163ccd3be4adcfa37e15608fb497be044113
- git.kernel.org/stable/c/58acd1f497162e7d282077f816faa519487be045
- git.kernel.org/stable/c/d798fd98e3563027c5162259ead517057d6fa794
- git.kernel.org/stable/c/f4a60d360d9114b5085701a3702a0102b0d6d846
Third-party and government advisories
- lists.debian.org/debian-lts-announce/2025/05/msg00045.htmlMailing List, Third Party Advisory
Recent Use After Free vulnerabilities
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 9.8 Critical severity
- 9.8 Critical severity
- 7.8 High severity
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