Linux: Use After Free
CVE-2025-37845 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 868df4eb784c3ccc7e4340a9ea993cbbedca167e, a27d2de2472b1cc7d582ab405d1d5832a80481de, 626f01f4d26e8cf92e69c1df53036153c8e98a20 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 868df4eb784c3ccc7e4340a9ea993cbbedca167e or a27d2de2472b1cc7d582ab405d1d5832a80481de or 626f01f4d26e8cf92e69c1df53036153c8e98a20 or dd941507a9486252d6fcf11814387666792020f3, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.12.24 or 6.13.12 or 6.14.3, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 71c9cf87776eaa556fc0a0a060df94200e1f521c up to, but not including, 868df4eb784c3ccc7e4340a9ea993cbbedca167e; 9db2b8cf4ea07b579db588e0353d5680f5d1f071 up to, but not including, a27d2de2472b1cc7d582ab405d1d5832a80481de; ac91052f0ae5be9e46211ba92cc31c0e3b0a933a up to, but not including, 626f01f4d26e8cf92e69c1df53036153c8e98a20; ac91052f0ae5be9e46211ba92cc31c0e3b0a933a up to, but not including, dd941507a9486252d6fcf11814387666792020f3; 6.12.21 up to, but not including, 6.12.24; 6.13.9 up to, but not including, 6.13.12; 6.14 | 868df4eb784c3ccc7e4340a9ea993cbbedca167e, a27d2de2472b1cc7d582ab405d1d5832a80481de, 626f01f4d26e8cf92e69c1df53036153c8e98a20, dd941507a9486252d6fcf11814387666792020f3, 6.12.24, 6.13.12 |
| Linux | Linux Kernel | 6.12.21 up to, but not including, 6.12.24; 6.13.9 up to, but not including, 6.13.12; 6.14.1 up to, but not including, 6.14.3; 6.14; 6.15 | 6.12.24, 6.13.12, 6.14.3 |
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 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: tracing: fprobe events: Fix possible UAF on modules Commit ac91052f0ae5 ("tracing: tprobe-events: Fix leakage of module refcount") moved try_module_get() from __find_tracepoint_module_cb() to find_tracepoint() caller, but that introduced a possible UAF because the module can be unloaded before try_module_get(). In this case, the module object should be freed too. Thus, try_module_get() does not only fail but may access to the freed object. To avoid that, try_module_get() in __find_tracepoint_module_cb() again.
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.
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
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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