Linux: Use After Free
CVE-2024-39494 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 480afcbeb7aaaa22677d3dd48ec590b441eaac1a, edf287bc610b18d7a9c0c0c1cb2e97b9348c71bb, 0b31e28fbd773aefb6164687e0767319b8199829 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 0.31% 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 480afcbeb7aaaa22677d3dd48ec590b441eaac1a or edf287bc610b18d7a9c0c0c1cb2e97b9348c71bb or 0b31e28fbd773aefb6164687e0767319b8199829 or 7fb374981e31c193b1152ed8d3b0a95b671330d4, whichever matches your release line, or a later version.
- Update Linux Kernel to 5.4.291 or 5.10.235 or 5.15.174 or 6.1.97, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 2fe5d6def1672ae6635dd71867bf36dcfaa7434b up to, but not including, 480afcbeb7aaaa22677d3dd48ec590b441eaac1a; 2fe5d6def1672ae6635dd71867bf36dcfaa7434b up to, but not including, edf287bc610b18d7a9c0c0c1cb2e97b9348c71bb; 2fe5d6def1672ae6635dd71867bf36dcfaa7434b up to, but not including, 0b31e28fbd773aefb6164687e0767319b8199829; 2fe5d6def1672ae6635dd71867bf36dcfaa7434b up to, but not including, 7fb374981e31c193b1152ed8d3b0a95b671330d4; 2fe5d6def1672ae6635dd71867bf36dcfaa7434b up to, but not including, dd431c3ac1fc34a9268580dd59ad3e3c76b32a8c; 2fe5d6def1672ae6635dd71867bf36dcfaa7434b up to, but not including, a78a6f0da57d058e2009e9958fdcef66f165208c; 2fe5d6def1672ae6635dd71867bf36dcfaa7434b up to, but not including, be84f32bb2c981ca670922e047cdde1488b233de; 3.7 | 480afcbeb7aaaa22677d3dd48ec590b441eaac1a, edf287bc610b18d7a9c0c0c1cb2e97b9348c71bb, 0b31e28fbd773aefb6164687e0767319b8199829, 7fb374981e31c193b1152ed8d3b0a95b671330d4, dd431c3ac1fc34a9268580dd59ad3e3c76b32a8c, a78a6f0da57d058e2009e9958fdcef66f165208c |
| Debian | Debian Linux | 11.0 | Not stated |
| Linux | Linux Kernel | 3.19 up to, but not including, 5.4.291; 5.5 up to, but not including, 5.10.235; 5.11 up to, but not including, 5.15.174; 5.16 up to, but not including, 6.1.97; 6.2 up to, but not including, 6.6.35; 6.7 up to, but not including, 6.9.6 | 5.4.291, 5.10.235, 5.15.174, 6.1.97, 6.6.35, 6.9.6 |
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: ima: Fix use-after-free on a dentry's dname.name ->d_name.name can change on rename and the earlier value can be freed; there are conditions sufficient to stabilize it (->d_lock on dentry, ->d_lock on its parent, ->i_rwsem exclusive on the parent's inode, rename_lock), but none of those are met at any of the sites. Take a stable snapshot of the name 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.
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/0b31e28fbd773aefb6164687e0767319b8199829
- git.kernel.org/stable/c/480afcbeb7aaaa22677d3dd48ec590b441eaac1a
- git.kernel.org/stable/c/7fb374981e31c193b1152ed8d3b0a95b671330d4
- git.kernel.org/stable/c/a78a6f0da57d058e2009e9958fdcef66f165208c
- git.kernel.org/stable/c/be84f32bb2c981ca670922e047cdde1488b233de
- git.kernel.org/stable/c/dd431c3ac1fc34a9268580dd59ad3e3c76b32a8c
- git.kernel.org/stable/c/edf287bc610b18d7a9c0c0c1cb2e97b9348c71bb
Third-party and government advisories
- lists.debian.org/debian-lts-announce/2025/01/msg00001.htmlMailing List, Third Party Advisory
- lists.debian.org/debian-lts-announce/2025/05/msg00030.htmlMailing List, Third Party Advisory
Recent Use After Free vulnerabilities
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
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