CVE-2021-20263 Privilege escalation in QEMU
A flaw in QEMU's virtiofsd allows guest users to retain security capabilities on file writes, potentially enabling privilege escalation within the guest.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2021-20263?
CVE-2021-20263 is a low-severity vulnerability in Qemu Qemu, published on 9 Mar 2021. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
A flaw was found in the virtio-fs shared file system daemon (virtiofsd) of QEMU. The new 'xattrmap' option may cause the 'security.capability' xattr in the guest to not drop on file write, potentially leading to a modified, privileged executable in the guest. In rare circumstances, this flaw could be used by a malicious user to elevate their privileges within the guest.
Weakness: CWE-281
Which versions are affected by CVE-2021-20263?
It affects 1 product.
Products include Qemu Qemu.
How do I fix CVE-2021-20263?
Apply the vendor's patch.
Is CVE-2021-20263 being exploited?
There is no known exploitation of CVE-2021-20263 in the wild and no public exploit code.
Other vulnerabilities in Qemu Qemu
Sources
Also known as DEBIAN-CVE-2021-20263, GHSA-349h-phx6-ghfj.