Linux: Use After Free
CVE-2024-35867 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 838ec01ea8d3deb5d123e8ed9022e8162dc3f503, bb6570085826291dc392005f9fec16ea5da3c8ad, 16b7d785775eb03929766819415055e367398f49 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 0.27% 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 838ec01ea8d3deb5d123e8ed9022e8162dc3f503 or bb6570085826291dc392005f9fec16ea5da3c8ad or 16b7d785775eb03929766819415055e367398f49 or c3cf8b74c57924c0985e49a1fdf02d3395111f39, whichever matches your release line, or a later version.
- Update Linux Kernel to 5.10.237 or 5.15.181 or 6.1.85 or 6.6.26, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 7f48558e6489d032b1584b0cc9ac4bb11072c034 up to, but not including, 838ec01ea8d3deb5d123e8ed9022e8162dc3f503; 7f48558e6489d032b1584b0cc9ac4bb11072c034 up to, but not including, bb6570085826291dc392005f9fec16ea5da3c8ad; 7f48558e6489d032b1584b0cc9ac4bb11072c034 up to, but not including, 16b7d785775eb03929766819415055e367398f49; 7f48558e6489d032b1584b0cc9ac4bb11072c034 up to, but not including, c3cf8b74c57924c0985e49a1fdf02d3395111f39; 7f48558e6489d032b1584b0cc9ac4bb11072c034 up to, but not including, 1e12f0d5c66f07c934041621351973a116fa13c7; 7f48558e6489d032b1584b0cc9ac4bb11072c034 up to, but not including, 0865ffefea197b437ba78b5dd8d8e256253efd65; a67172a013953664b1dad03c648200c70b90506c; 3.12.48 up to, but not including, 3.13; and 1 more ranges | 838ec01ea8d3deb5d123e8ed9022e8162dc3f503, bb6570085826291dc392005f9fec16ea5da3c8ad, 16b7d785775eb03929766819415055e367398f49, c3cf8b74c57924c0985e49a1fdf02d3395111f39, 1e12f0d5c66f07c934041621351973a116fa13c7, 0865ffefea197b437ba78b5dd8d8e256253efd65 |
| Debian | Debian Linux | 11.0 | Not stated |
| Linux | Linux Kernel | 4.20 up to, but not including, 5.10.237; 5.11 up to, but not including, 5.15.181; 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; 6.9 | 5.10.237, 5.15.181, 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.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.8 | High | CNA |
| CVSS 3.1 | 7.8 | High | NVD |
Official description
In the Linux kernel, the following vulnerability has been resolved: smb: client: fix potential UAF in cifs_stats_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.
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/0865ffefea197b437ba78b5dd8d8e256253efd65
- git.kernel.org/stable/c/16b7d785775eb03929766819415055e367398f49
- git.kernel.org/stable/c/1e12f0d5c66f07c934041621351973a116fa13c7
- git.kernel.org/stable/c/838ec01ea8d3deb5d123e8ed9022e8162dc3f503
- git.kernel.org/stable/c/bb6570085826291dc392005f9fec16ea5da3c8ad
- git.kernel.org/stable/c/c3cf8b74c57924c0985e49a1fdf02d3395111f39
Third-party and government advisories
- lists.debian.org/debian-lts-announce/2025/05/msg00030.htmlMailing List, Third Party Advisory
Other references
- openwall.com/lists/oss-security/2024/05/29/2Mailing List
- openwall.com/lists/oss-security/2024/05/30/1Mailing List
- openwall.com/lists/oss-security/2024/05/30/2Mailing List
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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