Linux: Use After Free
CVE-2022-49182 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 30f0ff7176efe8ac6c55f85bce26ed58bb608758, 09e383ca97e798f9954189b741af54b5c51e7a97, f58af41deeab0f45c9c80adf5f2de489ebbac3dd 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 0.28% 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 30f0ff7176efe8ac6c55f85bce26ed58bb608758 or 09e383ca97e798f9954189b741af54b5c51e7a97 or f58af41deeab0f45c9c80adf5f2de489ebbac3dd or 1932a624ab88ff407d1a1d567fe581faa15dc725, whichever matches your release line, or a later version.
- Update Linux Kernel to 5.15.33 or 5.16.19 or 5.17.2, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | c6075b193462d9a3930fb41f587f94720658752a up to, but not including, 30f0ff7176efe8ac6c55f85bce26ed58bb608758; c6075b193462d9a3930fb41f587f94720658752a up to, but not including, 09e383ca97e798f9954189b741af54b5c51e7a97; c6075b193462d9a3930fb41f587f94720658752a up to, but not including, f58af41deeab0f45c9c80adf5f2de489ebbac3dd; c6075b193462d9a3930fb41f587f94720658752a up to, but not including, 1932a624ab88ff407d1a1d567fe581faa15dc725; 5.1 | 30f0ff7176efe8ac6c55f85bce26ed58bb608758, 09e383ca97e798f9954189b741af54b5c51e7a97, f58af41deeab0f45c9c80adf5f2de489ebbac3dd, 1932a624ab88ff407d1a1d567fe581faa15dc725 |
| Linux | Linux Kernel | 5.1 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 | 5.15.33, 5.16.19, 5.17.2 |
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 CISA (ADP).
Official description
In the Linux kernel, the following vulnerability has been resolved: net: hns3: add vlan list lock to protect vlan list When adding port base VLAN, vf VLAN need to remove from HW and modify the vlan state in vf VLAN list as false. If the periodicity task is freeing the same node, it may cause "use after free" error. This patch adds a vlan list lock to protect the vlan list.
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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