CVE-2021-47111
What it is
In the Linux kernel, the following vulnerability has been resolved: xen-netback: take a reference to the RX task thread Do this in order to prevent the task from being freed if the thread returns (which can be triggered by the frontend) before the call to kthread_stop done as part of the backend tear down. Not taking the reference will lead to a use-after-free in that scenario. Such reference was taken before but dropped as part of the rework done in 2ac061ce97f4. Reintroduce the reference taking and add a comment this time explaining why it's needed. This is XSA-374 / CVE-2021-28691.
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: 8.8 HIGH (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.2% · EPSS, next 30 days
- Weakness
- CWE-416 · Use after free
- Record status
- Modified
Affected
- Linux Kernel < 5.10.43
- Linux Kernel < 5.12.10
- Linux Kernel 5.13
Attack profile CVSS 3.1 · 8.8
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Changed
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/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-2021-47111.md and follow it. Check whether this project is affected by CVE-2021-47111. 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/107866a8eb0b664675a260f1ba0655010fac1e08
- https://git.kernel.org/stable/c/6b53db8c4c14b4e7256f058d202908b54a7b85b4
- https://git.kernel.org/stable/c/caec9bcaeb1a5f03f2d406305355c853af10c13e
- https://git.kernel.org/stable/c/107866a8eb0b664675a260f1ba0655010fac1e08
- https://git.kernel.org/stable/c/6b53db8c4c14b4e7256f058d202908b54a7b85b4
- https://git.kernel.org/stable/c/caec9bcaeb1a5f03f2d406305355c853af10c13e
References
- https://git.kernel.org/stable/c/107866a8eb0b664675a260f1ba0655010fac1e08
- https://git.kernel.org/stable/c/6b53db8c4c14b4e7256f058d202908b54a7b85b4
- https://git.kernel.org/stable/c/caec9bcaeb1a5f03f2d406305355c853af10c13e
- https://git.kernel.org/stable/c/107866a8eb0b664675a260f1ba0655010fac1e08
- https://git.kernel.org/stable/c/6b53db8c4c14b4e7256f058d202908b54a7b85b4
- https://git.kernel.org/stable/c/caec9bcaeb1a5f03f2d406305355c853af10c13e