CVE-2021-4145 Null dereference in QEMU
A malicious guest user can crash the QEMU host process via a NULL pointer dereference in the block mirror layer, causing denial of service.
- 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-2021-4145?
CVE-2021-4145 is a medium-severity vulnerability in Qemu Qemu, published on 25 Jan 2022. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
A NULL pointer dereference issue was found in the block mirror layer of QEMU in versions prior to 6.2.0. The `self` pointer is dereferenced in mirror_wait_on_conflicts() without ensuring that it's not NULL. A malicious unprivileged user within the guest could use this flaw to crash the QEMU process on the host when writing data reaches the threshold of mirroring node.
Weakness: CWE-476
Which versions are affected by CVE-2021-4145?
It affects 2 products.
Products include Qemu Qemu, Redhat Enterprise Linux.
How do I fix CVE-2021-4145?
Upgrade to a fixed version.
Is CVE-2021-4145 being exploited?
There is no known exploitation of CVE-2021-4145 in the wild and no public exploit code.
Other vulnerabilities in Qemu Qemu
Sources
Also known as AZL-8347, DEBIAN-CVE-2021-4145, GHSA-j9qg-fc9x-6r3r.