Linux: Use After Free
CVE-2024-49991 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 e7831613cbbcd9058d3658fbcdc5d5884ceb2e0c, 30ceb873cc2e97348d9da2265b2d1ddf07f682e1, 71f3240f82987f0f070ea5bed559033de7d4c0e1 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 e7831613cbbcd9058d3658fbcdc5d5884ceb2e0c or 30ceb873cc2e97348d9da2265b2d1ddf07f682e1 or 71f3240f82987f0f070ea5bed559033de7d4c0e1 or 6c9289806591807e4e3be9a23df8ee2069180055, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.1.118 or 6.6.55 or 6.10.14 or 6.11.3, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 130e0371b7d454bb4a861253c822b9f911ad5d19 up to, but not including, e7831613cbbcd9058d3658fbcdc5d5884ceb2e0c; 130e0371b7d454bb4a861253c822b9f911ad5d19 up to, but not including, 30ceb873cc2e97348d9da2265b2d1ddf07f682e1; 130e0371b7d454bb4a861253c822b9f911ad5d19 up to, but not including, 71f3240f82987f0f070ea5bed559033de7d4c0e1; 130e0371b7d454bb4a861253c822b9f911ad5d19 up to, but not including, 6c9289806591807e4e3be9a23df8ee2069180055; 130e0371b7d454bb4a861253c822b9f911ad5d19 up to, but not including, c86ad39140bbcb9dc75a10046c2221f657e8083b; 4.3 | e7831613cbbcd9058d3658fbcdc5d5884ceb2e0c, 30ceb873cc2e97348d9da2265b2d1ddf07f682e1, 71f3240f82987f0f070ea5bed559033de7d4c0e1, 6c9289806591807e4e3be9a23df8ee2069180055, c86ad39140bbcb9dc75a10046c2221f657e8083b |
| Debian | Debian Linux | 11.0 | Not stated |
| Linux | Linux Kernel | before 6.1.118; 6.2 up to, but not including, 6.6.55; 6.7 up to, but not including, 6.10.14; 6.11 up to, but not including, 6.11.3 | 6.1.118, 6.6.55, 6.10.14, 6.11.3 |
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: drm/amdkfd: amdkfd_free_gtt_mem clear the correct pointer Pass pointer reference to amdgpu_bo_unref to clear the correct pointer, otherwise amdgpu_bo_unref clear the local variable, the original pointer not set to NULL, this could cause use-after-free bug.
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/30ceb873cc2e97348d9da2265b2d1ddf07f682e1
- git.kernel.org/stable/c/6c9289806591807e4e3be9a23df8ee2069180055
- git.kernel.org/stable/c/71f3240f82987f0f070ea5bed559033de7d4c0e1
- git.kernel.org/stable/c/c86ad39140bbcb9dc75a10046c2221f657e8083b
- git.kernel.org/stable/c/e7831613cbbcd9058d3658fbcdc5d5884ceb2e0c
Third-party and government advisories
- lists.debian.org/debian-lts-announce/2025/01/msg00001.htmlMailing List, Third Party Advisory
Recent Use After Free vulnerabilities
- 7.0 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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