Linux: Use After Free
CVE-2024-56651 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 4ad77eb8f2e07bcfa0e28887d3c7dbb732d92cc1, 1128022009444faf49359bd406cd665b177cb643, bc30b2fe8c54694f8ae08a5b8a5d174d16d93075 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 0.33% 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 4ad77eb8f2e07bcfa0e28887d3c7dbb732d92cc1 or 1128022009444faf49359bd406cd665b177cb643 or bc30b2fe8c54694f8ae08a5b8a5d174d16d93075 or 9ad86d377ef4a19c75a9c639964879a5b25a433b, whichever matches your release line, or a later version.
- Update Linux Kernel to 4.15 or 4.20 or 5.5 or 5.11, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | a22bd630cfff496b270211745536e50e98eb3a45 up to, but not including, 4ad77eb8f2e07bcfa0e28887d3c7dbb732d92cc1; a22bd630cfff496b270211745536e50e98eb3a45 up to, but not including, 1128022009444faf49359bd406cd665b177cb643; a22bd630cfff496b270211745536e50e98eb3a45 up to, but not including, bc30b2fe8c54694f8ae08a5b8a5d174d16d93075; a22bd630cfff496b270211745536e50e98eb3a45 up to, but not including, 9ad86d377ef4a19c75a9c639964879a5b25a433b; 303733fdab728d34708014b3096dc69ebae6e531; 410054f1cf75378a6f009359e5952a240102a1a2; d20bf7e76136fd4c1e47502a1f5773f2290013ed; 22e382d47de09e865a9214cc5c9f99256e65deaa; and 11 more ranges | 4ad77eb8f2e07bcfa0e28887d3c7dbb732d92cc1, 1128022009444faf49359bd406cd665b177cb643, bc30b2fe8c54694f8ae08a5b8a5d174d16d93075, 9ad86d377ef4a19c75a9c639964879a5b25a433b, 4.15, 4.20 |
| Linux | Linux Kernel | 4.14.291 up to, but not including, 4.15; 4.19.256 up to, but not including, 4.20; 5.4.211 up to, but not including, 5.5; 5.10.137 up to, but not including, 5.11; 5.15.61 up to, but not including, 5.16; 5.18.18 up to, but not including, 5.19; 5.19.2 up to, but not including, 5.20; 6.0 up to, but not including, 6.1.120; and 3 more ranges | 4.15, 4.20, 5.5, 5.11, 5.16, 5.19 |
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 | 8.8 | 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: can: hi311x: hi3110_can_ist(): fix potential use-after-free The commit a22bd630cfff ("can: hi311x: do not report txerr and rxerr during bus-off") removed the reporting of rxerr and txerr even in case of correct operation (i. e. not bus-off). The error count information added to the CAN frame after netif_rx() is a potential use after free, since there is no guarantee that the skb is in the same state. It might be freed or reused. Fix the issue by postponing the netif_rx() call in case of txerr and rxerr reporting.
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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