Linux: Use After Free
CVE-2022-49025 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 0a2d73a77060c3cbdc6e801cd5d979d674cd404b, 0d2f9d95d9fbe993f3c4bafb87d59897b0325aff, 372eb550faa0757349040fd43f59483cbfdb2c0b 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 0.25% 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 0a2d73a77060c3cbdc6e801cd5d979d674cd404b or 0d2f9d95d9fbe993f3c4bafb87d59897b0325aff or 372eb550faa0757349040fd43f59483cbfdb2c0b or e6d2d26a49c3a9cd46b232975e45236304810904, whichever matches your release line, or a later version.
- Update Linux Kernel to 5.4.226 or 5.10.158 or 5.15.82 or 6.0.12, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 10caabdaad5ace85577a453da97d1f8d3b944427 up to, but not including, 0a2d73a77060c3cbdc6e801cd5d979d674cd404b; 10caabdaad5ace85577a453da97d1f8d3b944427 up to, but not including, 0d2f9d95d9fbe993f3c4bafb87d59897b0325aff; 10caabdaad5ace85577a453da97d1f8d3b944427 up to, but not including, 372eb550faa0757349040fd43f59483cbfdb2c0b; 10caabdaad5ace85577a453da97d1f8d3b944427 up to, but not including, e6d2d26a49c3a9cd46b232975e45236304810904; 10caabdaad5ace85577a453da97d1f8d3b944427 up to, but not including, 52c795af04441d76f565c4634f893e5b553df2ae; 5.3 | 0a2d73a77060c3cbdc6e801cd5d979d674cd404b, 0d2f9d95d9fbe993f3c4bafb87d59897b0325aff, 372eb550faa0757349040fd43f59483cbfdb2c0b, e6d2d26a49c3a9cd46b232975e45236304810904, 52c795af04441d76f565c4634f893e5b553df2ae |
| Linux | Linux Kernel | 5.3 up to, but not including, 5.4.226; 5.5 up to, but not including, 5.10.158; 5.11 up to, but not including, 5.15.82; 5.16 up to, but not including, 6.0.12; 6.1 | 5.4.226, 5.10.158, 5.15.82, 6.0.12 |
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.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.8 | High | CNA |
| CVSS 3.1 | 7.8 | High | NVD |
Official description
In the Linux kernel, the following vulnerability has been resolved: net/mlx5e: Fix use-after-free when reverting termination table When having multiple dests with termination tables and second one or afterwards fails the driver reverts usage of term tables but doesn't reset the assignment in attr->dests[num_vport_dests].termtbl which case a use-after-free when releasing the rule. Fix by resetting the assignment of termtbl to null.
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/0a2d73a77060c3cbdc6e801cd5d979d674cd404b
- git.kernel.org/stable/c/0d2f9d95d9fbe993f3c4bafb87d59897b0325aff
- git.kernel.org/stable/c/372eb550faa0757349040fd43f59483cbfdb2c0b
- git.kernel.org/stable/c/52c795af04441d76f565c4634f893e5b553df2ae
- git.kernel.org/stable/c/e6d2d26a49c3a9cd46b232975e45236304810904
Recent Use After Free vulnerabilities
- 7.0 High severity
- 7.0 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
Spotted an error? Tell us.