Linux: Use After Free
CVE-2024-56605 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 f6ad641646b67f29c7578dcd6c25813c7dcbf51e, daa13175a6dea312a76099066cb4cbd4fc959a84, a8677028dd5123e5e525b8195483994d87123de4 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 f6ad641646b67f29c7578dcd6c25813c7dcbf51e or daa13175a6dea312a76099066cb4cbd4fc959a84 or a8677028dd5123e5e525b8195483994d87123de4 or bb2f2342a6ddf7c04f9aefbbfe86104cd138e629, 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 | 49dfbb9129c4edb318578de35cc45c555df37884 up to, but not including, f6ad641646b67f29c7578dcd6c25813c7dcbf51e; 49dfbb9129c4edb318578de35cc45c555df37884 up to, but not including, daa13175a6dea312a76099066cb4cbd4fc959a84; 49dfbb9129c4edb318578de35cc45c555df37884 up to, but not including, a8677028dd5123e5e525b8195483994d87123de4; 49dfbb9129c4edb318578de35cc45c555df37884 up to, but not including, bb2f2342a6ddf7c04f9aefbbfe86104cd138e629; 49dfbb9129c4edb318578de35cc45c555df37884 up to, but not including, 8ad09ddc63ace3950ac43db6fbfe25b40f589dd6; 49dfbb9129c4edb318578de35cc45c555df37884 up to, but not including, 61686abc2f3c2c67822aa23ce6f160467ec83d35; 49dfbb9129c4edb318578de35cc45c555df37884 up to, but not including, 7c4f78cdb8e7501e9f92d291a7d956591bf73be9; 3.6 | f6ad641646b67f29c7578dcd6c25813c7dcbf51e, daa13175a6dea312a76099066cb4cbd4fc959a84, a8677028dd5123e5e525b8195483994d87123de4, bb2f2342a6ddf7c04f9aefbbfe86104cd138e629, 8ad09ddc63ace3950ac43db6fbfe25b40f589dd6, 61686abc2f3c2c67822aa23ce6f160467ec83d35 |
| 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: Bluetooth: L2CAP: do not leave dangling sk pointer on error in l2cap_sock_create() bt_sock_alloc() allocates the sk object and attaches it to the provided sock object. On error l2cap_sock_alloc() frees the sk object, but the dangling pointer is still attached to the sock object, which may create use-after-free in other code.
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/61686abc2f3c2c67822aa23ce6f160467ec83d35
- git.kernel.org/stable/c/7c4f78cdb8e7501e9f92d291a7d956591bf73be9
- git.kernel.org/stable/c/8ad09ddc63ace3950ac43db6fbfe25b40f589dd6
- git.kernel.org/stable/c/a8677028dd5123e5e525b8195483994d87123de4
- git.kernel.org/stable/c/bb2f2342a6ddf7c04f9aefbbfe86104cd138e629
- git.kernel.org/stable/c/daa13175a6dea312a76099066cb4cbd4fc959a84
- git.kernel.org/stable/c/f6ad641646b67f29c7578dcd6c25813c7dcbf51e
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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