Linux: Use After Free
CVE-2023-54207 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 f78bb490b16ecb506d4904be4b00bf9aad6588f9, 51f49e3927ad545cec0c0afb86856ccacd9f085d, f283805d984343b2f216e2f4c6c7af265b9542ae 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 0.15% 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 f78bb490b16ecb506d4904be4b00bf9aad6588f9 or 51f49e3927ad545cec0c0afb86856ccacd9f085d or f283805d984343b2f216e2f4c6c7af265b9542ae or 4c2707dfee5847dc0b5ecfbe512c29c93832fdc4, whichever matches your release line, or a later version.
- Update Linux Kernel to 5.10.249 or 5.15.199 or 6.1.53 or 6.4.16, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | cce2dbdf258e6b27b2b100f511531edabb77f427 up to, but not including, f78bb490b16ecb506d4904be4b00bf9aad6588f9; cce2dbdf258e6b27b2b100f511531edabb77f427 up to, but not including, 51f49e3927ad545cec0c0afb86856ccacd9f085d; cce2dbdf258e6b27b2b100f511531edabb77f427 up to, but not including, f283805d984343b2f216e2f4c6c7af265b9542ae; cce2dbdf258e6b27b2b100f511531edabb77f427 up to, but not including, 4c2707dfee5847dc0b5ecfbe512c29c93832fdc4; cce2dbdf258e6b27b2b100f511531edabb77f427 up to, but not including, 58f0d1c0e494a88f301bf455da7df4366f179bbb; cce2dbdf258e6b27b2b100f511531edabb77f427 up to, but not including, dd613a4e45f8d35f49a63a2064e5308fa5619e29; 4.1 | f78bb490b16ecb506d4904be4b00bf9aad6588f9, 51f49e3927ad545cec0c0afb86856ccacd9f085d, f283805d984343b2f216e2f4c6c7af265b9542ae, 4c2707dfee5847dc0b5ecfbe512c29c93832fdc4, 58f0d1c0e494a88f301bf455da7df4366f179bbb, dd613a4e45f8d35f49a63a2064e5308fa5619e29 |
| Linux | Linux Kernel | 4.1 up to, but not including, 5.10.249; 5.11 up to, but not including, 5.15.199; 5.16 up to, but not including, 6.1.53; 6.2 up to, but not including, 6.4.16; 6.5 up to, but not including, 6.5.3 | 5.10.249, 5.15.199, 6.1.53, 6.4.16, 6.5.3 |
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.
Official description
In the Linux kernel, the following vulnerability has been resolved: HID: uclogic: Correct devm device reference for hidinput input_dev name Reference the HID device rather than the input device for the devm allocation of the input_dev name. Referencing the input_dev would lead to a use-after-free when the input_dev was unregistered and subsequently fires a uevent that depends on the name. At the point of firing the uevent, the name would be freed by devres management. Use devm_kasprintf to simplify the logic for allocating memory and formatting the input_dev name string.
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/4c2707dfee5847dc0b5ecfbe512c29c93832fdc4
- git.kernel.org/stable/c/51f49e3927ad545cec0c0afb86856ccacd9f085d
- git.kernel.org/stable/c/58f0d1c0e494a88f301bf455da7df4366f179bbb
- git.kernel.org/stable/c/dd613a4e45f8d35f49a63a2064e5308fa5619e29
- git.kernel.org/stable/c/f283805d984343b2f216e2f4c6c7af265b9542ae
- git.kernel.org/stable/c/f78bb490b16ecb506d4904be4b00bf9aad6588f9
Recent Use After Free vulnerabilities
- 7.5 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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