CVE-2021-3748
HIGH severity · CVSS 7.5 · Use-after-free
7.5CVSS HIGH
Summary
A use-after-free vulnerability was found in the virtio-net device of QEMU. It could occur when the descriptor's address belongs to the non direct access region, due to num_buffers being set after the virtqueue elem has been unmapped. A malicious guest could use this flaw to crash QEMU, resulting in a denial of service condition, or potentially execute code on the host with the privileges of the QEMU process.
Impact & exploitability
Attack vectorLocal
Attack complexityHigh
Privileges requiredHigh
User interactionNone
Confidentiality impactHigh
Integrity impactHigh
Availability impactHigh
Exploit probability (EPSS)1%
CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H
Affected products we track (1)
Recommendation
Apply the vendor fix promptly. Open any affected product above for its exact safe version.
Official patch: https://bugzilla.redhat.com/show_bug.cgi?id=1998514 ↗
Additional information
- NVD record
- https://bugzilla.redhat.com/show_bug.cgi?id=1998514Patch
- https://github.com/qemu/qemu/commit/bedd7e93d01961fcb16a97ae45d93acf357e11f6Patch
- https://lists.nongnu.org/archive/html/qemu-devel/2021-09/msg00388.htmlPatch
- https://ubuntu.com/security/CVE-2021-3748Patch
- https://lists.debian.org/debian-lts-announce/2022/04/msg00002.htmlAdvisory
- https://lists.debian.org/debian-lts-announce/2022/09/msg00008.htmlAdvisory
- https://security.gentoo.org/glsa/202208-27Advisory
- https://security.netapp.com/advisory/ntap-20220425-0004/Advisory