CVE-2021-20181 Use after free in qemu
A race condition in QEMU's 9pfs server allows malicious clients to trigger a use-after-free, leading to privilege escalation and potential code execution.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2021-20181?
CVE-2021-20181 is a high-severity use after free vulnerability in Debian Debian Linux, published on 13 May 2021. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
A race condition flaw was found in the 9pfs server implementation of QEMU up to and including 5.2.0. This flaw allows a malicious 9p client to cause a use-after-free error, potentially escalating their privileges on the system. The highest threat from this vulnerability is to confidentiality, integrity as well as system availability.
Which versions are affected by CVE-2021-20181?
It affects 2 products.
Products include Debian Debian Linux, Qemu Qemu.
How do I fix CVE-2021-20181?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2021-20181 being exploited?
There is no known exploitation of CVE-2021-20181 in the wild and no public exploit code.
Other vulnerabilities in Debian Debian Linux
Sources
Also known as DEBIAN-CVE-2021-20181, GHSA-mq7v-47j3-rc24, OESA-2021-1218, UBUNTU-CVE-2021-20181.