Linux: Use After Free
CVE-2024-56603 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 884ae8bcee749be43a071d6ed2d89058dbd2425c, ce39b5576785bb3e66591145aad03d66bc3e778d, 1fe625f12d090d69f3f084990c7e4c1ff94bfe5f 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 0.24% 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 884ae8bcee749be43a071d6ed2d89058dbd2425c or ce39b5576785bb3e66591145aad03d66bc3e778d or 1fe625f12d090d69f3f084990c7e4c1ff94bfe5f or 5947c9ac08f0771ea8ed64186b0d52e9029cb6c0, whichever matches your release line, or a later version.
- Update Linux Kernel to 5.4.287 or 5.10.231 or 5.15.174 or 6.1.120, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 0d66548a10cbbe0ef256852d63d30603f0f73f9b up to, but not including, 884ae8bcee749be43a071d6ed2d89058dbd2425c; 0d66548a10cbbe0ef256852d63d30603f0f73f9b up to, but not including, ce39b5576785bb3e66591145aad03d66bc3e778d; 0d66548a10cbbe0ef256852d63d30603f0f73f9b up to, but not including, 1fe625f12d090d69f3f084990c7e4c1ff94bfe5f; 0d66548a10cbbe0ef256852d63d30603f0f73f9b up to, but not including, 5947c9ac08f0771ea8ed64186b0d52e9029cb6c0; 0d66548a10cbbe0ef256852d63d30603f0f73f9b up to, but not including, db207d19adbac96058685f6257720906ad41d215; 0d66548a10cbbe0ef256852d63d30603f0f73f9b up to, but not including, 8df832e6b945e1ba61467d7f1c9305e314ae92fe; 0d66548a10cbbe0ef256852d63d30603f0f73f9b up to, but not including, 811a7ca7320c062e15d0f5b171fe6ad8592d1434; 2.6.25 | 884ae8bcee749be43a071d6ed2d89058dbd2425c, ce39b5576785bb3e66591145aad03d66bc3e778d, 1fe625f12d090d69f3f084990c7e4c1ff94bfe5f, 5947c9ac08f0771ea8ed64186b0d52e9029cb6c0, db207d19adbac96058685f6257720906ad41d215, 8df832e6b945e1ba61467d7f1c9305e314ae92fe |
| Linux | Linux Kernel | before 5.4.287; 5.5 up to, but not including, 5.10.231; 5.11 up to, but not including, 5.15.174; 5.16 up to, but not including, 6.1.120; 6.2 up to, but not including, 6.6.66; 6.7 up to, but not including, 6.12.5 | 5.4.287, 5.10.231, 5.15.174, 6.1.120, 6.6.66, 6.12.5 |
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 | NVD |
| CVSS 3.1 | 7.8 | High | CISA (ADP) |
Official description
In the Linux kernel, the following vulnerability has been resolved: net: af_can: do not leave a dangling sk pointer in can_create() On error can_create() frees the allocated sk object, but sock_init_data() has already attached it to the provided sock object. This will leave a dangling sk pointer in the sock object and may cause use-after-free later.
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
- git.kernel.org/stable/c/1fe625f12d090d69f3f084990c7e4c1ff94bfe5f
- git.kernel.org/stable/c/5947c9ac08f0771ea8ed64186b0d52e9029cb6c0
- git.kernel.org/stable/c/811a7ca7320c062e15d0f5b171fe6ad8592d1434
- git.kernel.org/stable/c/884ae8bcee749be43a071d6ed2d89058dbd2425c
- git.kernel.org/stable/c/8df832e6b945e1ba61467d7f1c9305e314ae92fe
- git.kernel.org/stable/c/ce39b5576785bb3e66591145aad03d66bc3e778d
- git.kernel.org/stable/c/db207d19adbac96058685f6257720906ad41d215
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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