Linux: Use After Free
CVE-2023-53552 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 8017a27cec32eac8c8f9430b0a3055840136b856, 7fb464d52fa41c31a6fd1ad82888e67c65935d94, 5eefc5307c983b59344a4cb89009819f580c84fa 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 0.17% 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 8017a27cec32eac8c8f9430b0a3055840136b856 or 7fb464d52fa41c31a6fd1ad82888e67c65935d94 or 5eefc5307c983b59344a4cb89009819f580c84fa, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.1.54 or 6.5.4, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | bcb9aa45d5a0e11ef91245330c53cde214d15e8d up to, but not including, 8017a27cec32eac8c8f9430b0a3055840136b856; bcb9aa45d5a0e11ef91245330c53cde214d15e8d up to, but not including, 7fb464d52fa41c31a6fd1ad82888e67c65935d94; bcb9aa45d5a0e11ef91245330c53cde214d15e8d up to, but not including, 5eefc5307c983b59344a4cb89009819f580c84fa; 6.0 | 8017a27cec32eac8c8f9430b0a3055840136b856, 7fb464d52fa41c31a6fd1ad82888e67c65935d94, 5eefc5307c983b59344a4cb89009819f580c84fa |
| Linux | Linux Kernel | 6.0 up to, but not including, 6.1.54; 6.2 up to, but not including, 6.5.4 | 6.1.54, 6.5.4 |
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: drm/i915: mark requests for GuC virtual engines to avoid use-after-free References to i915_requests may be trapped by userspace inside a sync_file or dmabuf (dma-resv) and held indefinitely across different proceses. To counter-act the memory leaks, we try to not to keep references from the request past their completion. On the other side on fence release we need to know if rq->engine is valid and points to hw engine (true for non-virtual requests). To make it possible extra bit has been added to rq->execution_mask, for marking virtual engines. (cherry picked from commit 280410677af763f3871b93e794a199cfcf6fb580)
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
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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