CVE-2021-46971
What it is
In the Linux kernel, the following vulnerability has been resolved: perf/core: Fix unconditional security_locked_down() call Currently, the lockdown state is queried unconditionally, even though its result is used only if the PERF_SAMPLE_REGS_INTR bit is set in attr.sample_type. While that doesn't matter in case of the Lockdown LSM, it causes trouble with the SELinux's lockdown hook implementation. SELinux implements the locked_down hook with a check whether the current task's type has the corresponding "lockdown" class permission ("integrity" or "confidentiality") allowed in the policy. This means that calling the hook when the access control decision would be ignored generates a bogus permission check and audit record. Fix this by checking sample_type first and only calling the hook when its result would be honored.
At a glance
- Exploitability
- Can be exploited locally on the machine with a low-privilege account. Limited direct impact.
- Exploit odds
- 0.2% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.2% in the next 30 days (EPSS).
- Severity: 3.3 LOW (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.2% · EPSS, next 30 days
- Record status
- Analyzed
Affected
- Linux Kernel < 5.4.117
- Linux Kernel < 5.10.35
- Linux Kernel < 5.11.19
- Linux Kernel < 5.12.2
Attack profile CVSS 3.1 · 3.3
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- Low
- Availability
- None
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2021-46971.md and follow it. Check whether this project is affected by CVE-2021-46971. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://git.kernel.org/stable/c/08ef1af4de5fe7de9c6d69f1e22e51b66e385d9b
- https://git.kernel.org/stable/c/4348d3b5027bc3ff6336368b6c60605d4ef8e1ce
- https://git.kernel.org/stable/c/b246759284d6a2bc5b6f1009caeeb3abce2ec9ff
- https://git.kernel.org/stable/c/c7b0208ee370b89d20486fae71cd9abb759819c1
- https://git.kernel.org/stable/c/f5809ca4c311b71bfaba6d13f4e39eab0557895e
- https://git.kernel.org/stable/c/08ef1af4de5fe7de9c6d69f1e22e51b66e385d9b
- https://git.kernel.org/stable/c/4348d3b5027bc3ff6336368b6c60605d4ef8e1ce
- https://git.kernel.org/stable/c/b246759284d6a2bc5b6f1009caeeb3abce2ec9ff
- https://git.kernel.org/stable/c/c7b0208ee370b89d20486fae71cd9abb759819c1
- https://git.kernel.org/stable/c/f5809ca4c311b71bfaba6d13f4e39eab0557895e
References
- https://git.kernel.org/stable/c/08ef1af4de5fe7de9c6d69f1e22e51b66e385d9b
- https://git.kernel.org/stable/c/4348d3b5027bc3ff6336368b6c60605d4ef8e1ce
- https://git.kernel.org/stable/c/b246759284d6a2bc5b6f1009caeeb3abce2ec9ff
- https://git.kernel.org/stable/c/c7b0208ee370b89d20486fae71cd9abb759819c1
- https://git.kernel.org/stable/c/f5809ca4c311b71bfaba6d13f4e39eab0557895e
- https://git.kernel.org/stable/c/08ef1af4de5fe7de9c6d69f1e22e51b66e385d9b
- https://git.kernel.org/stable/c/4348d3b5027bc3ff6336368b6c60605d4ef8e1ce
- https://git.kernel.org/stable/c/b246759284d6a2bc5b6f1009caeeb3abce2ec9ff
- https://git.kernel.org/stable/c/c7b0208ee370b89d20486fae71cd9abb759819c1
- https://git.kernel.org/stable/c/f5809ca4c311b71bfaba6d13f4e39eab0557895e