Linux: Improper Locking
CVE-2024-27021 is a high-severity improper locking 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 53d986f39acd8ea11c9e460732bfa5add66360d9, 19fa4f2a85d777a8052e869c1b892a2f7556569d 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 0.18% 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 53d986f39acd8ea11c9e460732bfa5add66360d9 or 19fa4f2a85d777a8052e869c1b892a2f7556569d, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.8.8 or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 18764b883e157e28126b54e7d4ba9dd487d5bf54 up to, but not including, 53d986f39acd8ea11c9e460732bfa5add66360d9; 18764b883e157e28126b54e7d4ba9dd487d5bf54 up to, but not including, 19fa4f2a85d777a8052e869c1b892a2f7556569d; 6.8 | 53d986f39acd8ea11c9e460732bfa5add66360d9, 19fa4f2a85d777a8052e869c1b892a2f7556569d |
| Linux | Linux Kernel | 6.8 up to, but not including, 6.8.8; 6.9 | 6.8.8 |
| Fedora Project | Fedora | 38; 39; 40 | Not stated |
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
In the Linux kernel, the following vulnerability has been resolved: r8169: fix LED-related deadlock on module removal Binding devm_led_classdev_register() to the netdev is problematic because on module removal we get a RTNL-related deadlock. Fix this by avoiding the device-managed LED functions. Note: We can safely call led_classdev_unregister() for a LED even if registering it failed, because led_classdev_unregister() detects this and is a no-op in this case.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Locking
The product does not properly acquire or release a lock on a resource, leading to unexpected resource state changes and behaviors.
How developers prevent this class of flaw
- Use industry standard APIs to implement locking mechanism.
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 Improper Locking vulnerabilities
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.5 High severity
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