Linux: Use After Free
CVE-2022-49129 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 38fbe806645090c07aa97171f20fc62c3d7d3a98, c1a5e6002ec441a3b9fb4d048b4b49ae93409a46, ac1260b661c2ef0d0a56680cdb5672b931b7be8f 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 0.27% 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 38fbe806645090c07aa97171f20fc62c3d7d3a98 or c1a5e6002ec441a3b9fb4d048b4b49ae93409a46 or ac1260b661c2ef0d0a56680cdb5672b931b7be8f or 827e7799c61b978fbc2cc9dac66cb62401b2b3f0, whichever matches your release line, or a later version.
- Update Linux Kernel to 5.15.34 or 5.16.20 or 5.17.3, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 0c1ce988460765ece1ba8eacd00533eefb6e666a up to, but not including, 38fbe806645090c07aa97171f20fc62c3d7d3a98; 0c1ce988460765ece1ba8eacd00533eefb6e666a up to, but not including, c1a5e6002ec441a3b9fb4d048b4b49ae93409a46; 0c1ce988460765ece1ba8eacd00533eefb6e666a up to, but not including, ac1260b661c2ef0d0a56680cdb5672b931b7be8f; 0c1ce988460765ece1ba8eacd00533eefb6e666a up to, but not including, 827e7799c61b978fbc2cc9dac66cb62401b2b3f0; bea85ed1f508023e1586ede6a622f35fe910857b; 5.12.16 up to, but not including, 5.13; 5.13 | 38fbe806645090c07aa97171f20fc62c3d7d3a98, c1a5e6002ec441a3b9fb4d048b4b49ae93409a46, ac1260b661c2ef0d0a56680cdb5672b931b7be8f, 827e7799c61b978fbc2cc9dac66cb62401b2b3f0, 5.13 |
| Linux | Linux Kernel | 4.16 up to, but not including, 5.15.34; 5.16 up to, but not including, 5.16.20; 5.17 up to, but not including, 5.17.3 | 5.15.34, 5.16.20, 5.17.3 |
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 CNA.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.8 | High | CNA |
| CVSS 3.1 | 7.8 | High | CISA (ADP) |
Official description
In the Linux kernel, the following vulnerability has been resolved: mt76: mt7921: fix crash when startup fails. If the nic fails to start, it is possible that the reset_work has already been scheduled. Ensure the work item is canceled so we do not have use-after-free crash in case cleanup is called before the work item is executed. This fixes crash on my x86_64 apu2 when mt7921k radio fails to work. Radio still fails, but OS does not crash.
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
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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