Linux: Use After Free
CVE-2023-52777 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 0cf7577b6b3153b4b49deea9719fe43f96469c6d, cf9c7d783a2bf9305df4ef5b93d9063a52e18fca, e83246ecd3b193f8d91fce778e8a5ba747fc7d8a 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 0cf7577b6b3153b4b49deea9719fe43f96469c6d or cf9c7d783a2bf9305df4ef5b93d9063a52e18fca or e83246ecd3b193f8d91fce778e8a5ba747fc7d8a or 1dea3c0720a146bd7193969f2847ccfed5be2221, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.1.64 or 6.5.13 or 6.6.3, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | a16d9b50cfbaf112401b8e5ccfa852709f498cd4 up to, but not including, 0cf7577b6b3153b4b49deea9719fe43f96469c6d; a16d9b50cfbaf112401b8e5ccfa852709f498cd4 up to, but not including, cf9c7d783a2bf9305df4ef5b93d9063a52e18fca; a16d9b50cfbaf112401b8e5ccfa852709f498cd4 up to, but not including, e83246ecd3b193f8d91fce778e8a5ba747fc7d8a; a16d9b50cfbaf112401b8e5ccfa852709f498cd4 up to, but not including, 1dea3c0720a146bd7193969f2847ccfed5be2221; 5.19 | 0cf7577b6b3153b4b49deea9719fe43f96469c6d, cf9c7d783a2bf9305df4ef5b93d9063a52e18fca, e83246ecd3b193f8d91fce778e8a5ba747fc7d8a, 1dea3c0720a146bd7193969f2847ccfed5be2221 |
| Linux | Linux Kernel | 5.19 up to, but not including, 6.1.64; 6.2 up to, but not including, 6.5.13; 6.6 up to, but not including, 6.6.3 | 6.1.64, 6.5.13, 6.6.3 |
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: wifi: ath11k: fix gtk offload status event locking The ath11k active pdevs are protected by RCU but the gtk offload status event handling code calling ath11k_mac_get_arvif_by_vdev_id() was not marked as a read-side critical section. Mark the code in question as an RCU read-side critical section to avoid any potential use-after-free issues. Compile tested only.
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
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
Spotted an error? Tell us.