Linux: Use After Free
CVE-2024-50061 is a high-severity use after free vulnerability in Linux, with a CVSS 3.1 base score of 7.0 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 2a21bad9964c91b34d65ba269914233720c0b1ce, ea0256e393e0072e8c80fd941547807f0c28108b, 687016d6a1efbfacdd2af913e2108de6b75a28d5 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 0.21% 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 2a21bad9964c91b34d65ba269914233720c0b1ce or ea0256e393e0072e8c80fd941547807f0c28108b or 687016d6a1efbfacdd2af913e2108de6b75a28d5 or 609366e7a06d035990df78f1562291c3bf0d4a12, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.6.57 or 6.11.4, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 3a379bbcea0af6280e1ca0d1edfcf4e68cde6ee0 up to, but not including, 2a21bad9964c91b34d65ba269914233720c0b1ce; 3a379bbcea0af6280e1ca0d1edfcf4e68cde6ee0 up to, but not including, ea0256e393e0072e8c80fd941547807f0c28108b; 3a379bbcea0af6280e1ca0d1edfcf4e68cde6ee0 up to, but not including, 687016d6a1efbfacdd2af913e2108de6b75a28d5; 3a379bbcea0af6280e1ca0d1edfcf4e68cde6ee0 up to, but not including, 609366e7a06d035990df78f1562291c3bf0d4a12; 5.0 | 2a21bad9964c91b34d65ba269914233720c0b1ce, ea0256e393e0072e8c80fd941547807f0c28108b, 687016d6a1efbfacdd2af913e2108de6b75a28d5, 609366e7a06d035990df78f1562291c3bf0d4a12 |
| Linux | Linux Kernel | before 6.6.57; 6.7 up to, but not including, 6.11.4 | 6.6.57, 6.11.4 |
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
- HighSuccess depends on conditions outside the attacker's control.
- 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:H/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: i3c: master: cdns: Fix use after free vulnerability in cdns_i3c_master Driver Due to Race Condition In the cdns_i3c_master_probe function, &master->hj_work is bound with cdns_i3c_master_hj. And cdns_i3c_master_interrupt can call cnds_i3c_master_demux_ibis function to start the work. If we remove the module which will call cdns_i3c_master_remove to make cleanup, it will free master->base through i3c_master_unregister while the work mentioned above will be used. The sequence of operations that may lead to a UAF bug is as follows: CPU0 CPU1 | cdns_i3c_master_hj cdns_i3c_master_remove | i3c_master_unregister(&master->base) | device_unregister(&master->dev) | device_release | //free master->base | | i3c_master_do_daa(&master->base) | //use master->base Fix it by ensuring that the work is canceled before proceeding with the cleanup in cdns_i3c_master_remove.
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
Other references
Recent Use After Free vulnerabilities
- 7.0 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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