CVE-2021-4145MediumCVSS 6.5
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.
🔗 CVE IDs covered (1)
📋 Description
Is Azure Linux the only Microsoft product that includes this open-source library and is therefore potentially affected by this vulnerability? One of the main benefits to our customers who choose to use the Azure Linux distro is the commitment to keep it up to date with the most recent and most secure versions of the open source libraries with which the distro is composed. Microsoft is committed to transparency in this work which is why we began publishing CSAF/VEX in October 2025. See this blog post for more information. If impact to additional products is identified, we will update the CVE to reflect this.
🎯 Affected products1
- cbl2 qemu 6.2.0-2 on CBL Mariner 2.0
✅ Remediation
KBCBL-Mariner Releases (Security Update) — fixed build 6.2.0-2