Linux: Use After Free
CVE-2024-50286 is a high-severity use after free vulnerability in Linux, with a CVSS 3.1 base score of 7.0 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 f56446ba5378d19e31040b548a14ee9a8f1500ea, e923503a56b3385b64ae492e3225e4623f560c5b, e7a2ad2044377853cf8c59528dac808a08a99c72 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 0.68% chance of exploitation within 30 days, higher than 53% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Linux to f56446ba5378d19e31040b548a14ee9a8f1500ea or e923503a56b3385b64ae492e3225e4623f560c5b or e7a2ad2044377853cf8c59528dac808a08a99c72 or 0a77715db22611df50b178374c51e2ba0d58866e, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.1.117 or 6.6.61 or 6.11.8, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 0626e6641f6b467447c81dd7678a69c66f7746cf up to, but not including, f56446ba5378d19e31040b548a14ee9a8f1500ea; 0626e6641f6b467447c81dd7678a69c66f7746cf up to, but not including, e923503a56b3385b64ae492e3225e4623f560c5b; 0626e6641f6b467447c81dd7678a69c66f7746cf up to, but not including, e7a2ad2044377853cf8c59528dac808a08a99c72; 0626e6641f6b467447c81dd7678a69c66f7746cf up to, but not including, 0a77715db22611df50b178374c51e2ba0d58866e; 5.15 | f56446ba5378d19e31040b548a14ee9a8f1500ea, e923503a56b3385b64ae492e3225e4623f560c5b, e7a2ad2044377853cf8c59528dac808a08a99c72, 0a77715db22611df50b178374c51e2ba0d58866e |
| Linux | Linux Kernel | before 6.1.117; 6.2 up to, but not including, 6.6.61; 6.7 up to, but not including, 6.11.8; 6.12 | 6.1.117, 6.6.61, 6.11.8 |
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
- HighSuccess depends on conditions outside the attacker's control.
- 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:H/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 9.8 | Critical | CNA |
| CVSS 3.1 | 7.0 | High | NVD |
| CVSS 3.1 | 7.8 | High | CISA (ADP) |
Official description
In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix slab-use-after-free in ksmbd_smb2_session_create There is a race condition between ksmbd_smb2_session_create and ksmbd_expire_session. This patch add missing sessions_table_lock while adding/deleting session from global session table.
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: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Other references
Recent Use After Free vulnerabilities
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