Linux: Use After Free
CVE-2024-56538 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 0c8ca1da81e5a9787284eb84c0c6ae927f063c15, a17b9afe58c474657449cf87e238b1788200576b, 4fb97432e28a7e136b2d76135d50e988ada8e1af 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 0c8ca1da81e5a9787284eb84c0c6ae927f063c15 or a17b9afe58c474657449cf87e238b1788200576b or 4fb97432e28a7e136b2d76135d50e988ada8e1af or 692f52aedccbf79b212a1e14e3735192b4c24a7d, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.6.64 or 6.11.11 or 6.12.2, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | d76271d22694e874ed70791702db9252ffe96a4c up to, but not including, 0c8ca1da81e5a9787284eb84c0c6ae927f063c15; d76271d22694e874ed70791702db9252ffe96a4c up to, but not including, a17b9afe58c474657449cf87e238b1788200576b; d76271d22694e874ed70791702db9252ffe96a4c up to, but not including, 4fb97432e28a7e136b2d76135d50e988ada8e1af; d76271d22694e874ed70791702db9252ffe96a4c up to, but not including, 692f52aedccbf79b212a1e14e3735192b4c24a7d; d76271d22694e874ed70791702db9252ffe96a4c up to, but not including, 2e07c88914fc5289c21820b1aa94f058feb38197; 5.9 | 0c8ca1da81e5a9787284eb84c0c6ae927f063c15, a17b9afe58c474657449cf87e238b1788200576b, 4fb97432e28a7e136b2d76135d50e988ada8e1af, 692f52aedccbf79b212a1e14e3735192b4c24a7d, 2e07c88914fc5289c21820b1aa94f058feb38197 |
| Linux | Linux Kernel | 5.9 up to, but not including, 6.6.64; 6.7 up to, but not including, 6.11.11; 6.12 up to, but not including, 6.12.2 | 6.6.64, 6.11.11, 6.12.2 |
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 |
| CVSS 3.1 | 7.8 | High | CISA (ADP) |
Official description
In the Linux kernel, the following vulnerability has been resolved: drm: zynqmp_kms: Unplug DRM device before removal Prevent userspace accesses to the DRM device from causing use-after-frees by unplugging the device before we remove it. This causes any further userspace accesses to result in an error without further calls into this driver's internals.
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
- 7.8 High severity
- 7.0 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
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