CVE-2021-47461
What it is
In the Linux kernel, the following vulnerability has been resolved: userfaultfd: fix a race between writeprotect and exit_mmap() A race is possible when a process exits, its VMAs are removed by exit_mmap() and at the same time userfaultfd_writeprotect() is called. The race was detected by KASAN on a development kernel, but it appears to be possible on vanilla kernels as well. Use mmget_not_zero() to prevent the race as done in other userfaultfd operations.
At a glance
- Exploitability
- Can be exploited locally on the machine with a low-privilege account. High risk of data exposure, data tampering, service disruption.
- 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: 7.8 HIGH (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.2% · EPSS, next 30 days
- Weakness
- CWE-362 · Race condition
- Record status
- Modified
Affected
- Linux Kernel < 5.10.76
- Linux Kernel < 5.14.15
- Linux Kernel 5.15
Attack profile CVSS 3.1 · 7.8
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
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-2021-47461.md and follow it. Check whether this project is affected by CVE-2021-47461. 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/149958ecd0627a9f1e9c678c25c665400054cd6a
- https://git.kernel.org/stable/c/3cda4bfffd4f755645577aaa9e96a606657b4525
- https://git.kernel.org/stable/c/cb185d5f1ebf900f4ae3bf84cee212e6dd035aca
- https://git.kernel.org/stable/c/149958ecd0627a9f1e9c678c25c665400054cd6a
- https://git.kernel.org/stable/c/3cda4bfffd4f755645577aaa9e96a606657b4525
- https://git.kernel.org/stable/c/cb185d5f1ebf900f4ae3bf84cee212e6dd035aca
References
- https://git.kernel.org/stable/c/149958ecd0627a9f1e9c678c25c665400054cd6a
- https://git.kernel.org/stable/c/3cda4bfffd4f755645577aaa9e96a606657b4525
- https://git.kernel.org/stable/c/cb185d5f1ebf900f4ae3bf84cee212e6dd035aca
- https://git.kernel.org/stable/c/149958ecd0627a9f1e9c678c25c665400054cd6a
- https://git.kernel.org/stable/c/3cda4bfffd4f755645577aaa9e96a606657b4525
- https://git.kernel.org/stable/c/cb185d5f1ebf900f4ae3bf84cee212e6dd035aca