Linux: Use After Free
CVE-2023-52475 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 8677575c4f39d65bf0d719b5d20e8042e550ccb9, 67cace72606baf1758fd60feb358f4c6be92e1cc, 5aa514100aaf59868d745196258269a16737c7bd 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 0.23% 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 8677575c4f39d65bf0d719b5d20e8042e550ccb9 or 67cace72606baf1758fd60feb358f4c6be92e1cc or 5aa514100aaf59868d745196258269a16737c7bd or cd2fbfd8b922b7fdd50732e47d797754ab59cb06, whichever matches your release line, or a later version.
- Update Linux Kernel to 4.14.328 or 4.19.297 or 5.4.259 or 5.10.199, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, 8677575c4f39d65bf0d719b5d20e8042e550ccb9; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, 67cace72606baf1758fd60feb358f4c6be92e1cc; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, 5aa514100aaf59868d745196258269a16737c7bd; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, cd2fbfd8b922b7fdd50732e47d797754ab59cb06; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, 6a4a396386404e62fb59bc3bde48871a64a82b4f; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, 2efe67c581a2a6122b328d4bb6f21b3f36f40d46; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, e528b1b9d60743e0b26224e3fe7aa74c24b8b2f8; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, 5c15c60e7be615f05a45cd905093a54b11f461bc; and 1 more ranges | 8677575c4f39d65bf0d719b5d20e8042e550ccb9, 67cace72606baf1758fd60feb358f4c6be92e1cc, 5aa514100aaf59868d745196258269a16737c7bd, cd2fbfd8b922b7fdd50732e47d797754ab59cb06, 6a4a396386404e62fb59bc3bde48871a64a82b4f, 2efe67c581a2a6122b328d4bb6f21b3f36f40d46 |
| Linux | Linux Kernel | before 4.14.328; 4.15 up to, but not including, 4.19.297; 4.20 up to, but not including, 5.4.259; 5.5 up to, but not including, 5.10.199; 5.11 up to, but not including, 5.15.136; 5.16 up to, but not including, 6.1.59; 6.2 up to, but not including, 6.5.8; 6.6 | 4.14.328, 4.19.297, 5.4.259, 5.10.199, 5.15.136, 6.1.59 |
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.
Official description
In the Linux kernel, the following vulnerability has been resolved: Input: powermate - fix use-after-free in powermate_config_complete syzbot has found a use-after-free bug [1] in the powermate driver. This happens when the device is disconnected, which leads to a memory free from the powermate_device struct. When an asynchronous control message completes after the kfree and its callback is invoked, the lock does not exist anymore and hence the bug. Use usb_kill_urb() on pm->config to cancel any in-progress requests upon device disconnection. [1] https://syzkaller.appspot.com/bug?extid=0434ac83f907a1dbdd1e
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/2efe67c581a2a6122b328d4bb6f21b3f36f40d46
- git.kernel.org/stable/c/5aa514100aaf59868d745196258269a16737c7bd
- git.kernel.org/stable/c/5c15c60e7be615f05a45cd905093a54b11f461bc
- git.kernel.org/stable/c/67cace72606baf1758fd60feb358f4c6be92e1cc
- git.kernel.org/stable/c/6a4a396386404e62fb59bc3bde48871a64a82b4f
- git.kernel.org/stable/c/8677575c4f39d65bf0d719b5d20e8042e550ccb9
- git.kernel.org/stable/c/cd2fbfd8b922b7fdd50732e47d797754ab59cb06
- git.kernel.org/stable/c/e528b1b9d60743e0b26224e3fe7aa74c24b8b2f8
Recent Use After Free vulnerabilities
- 7.8 High severity
- 7.8 High severity
- 7.5 High severity
- 9.8 Critical severity
- 7.8 High severity
- 8.1 High severity
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