Kernel: Use After Free
CVE-2022-3239 is a high-severity use after free vulnerability in Kernel, 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. Affected Kernel versions: Linux kernel 5.18-rc1. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.26% 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 Kernel to 4.14.295 or 4.19.238 or 5.4.189 or 5.10.110, whichever matches your release line, or a later version.
- Read the advisory on git.kernel.org for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Kernel | Kernel | Linux kernel 5.18-rc1 | Not stated |
| Linux | Linux Kernel | 3.15 up to, but not including, 4.14.295; 4.15 up to, but not including, 4.19.238; 4.20 up to, but not including, 5.4.189; 5.5 up to, but not including, 5.10.110; 5.11 up to, but not including, 5.15.33; 5.16 up to, but not including, 5.16.19; 5.17 up to, but not including, 5.17.2 | 4.14.295, 4.19.238, 5.4.189, 5.10.110, 5.15.33, 5.16.19 |
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
A flaw use after free in the Linux kernel video4linux driver was found in the way user triggers em28xx_usb_probe() for the Empia 28xx based TV cards. A local user could use this flaw to crash the system or potentially escalate their privileges on the system.
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.
- Record last changed materially (score, affected products, status or references).
References
Advisories
Other references
Other vulnerabilities in Kernel
- 7.5 High severity
- 7.8 High severity
- 8.1 High severity
- 7.1 High severity
- 8.1 High severity
- 8.1 High severity
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
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