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.
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.
| Link | Tags |
|---|---|
| https://bugzilla.redhat.com/show_bug.cgi?id=1998514 | patch third party advisory issue tracking |
| https://ubuntu.com/security/CVE-2021-3748 | third party advisory patch |
| https://github.com/qemu/qemu/commit/bedd7e93d01961fcb16a97ae45d93acf357e11f6 | third party advisory patch |
| https://lists.nongnu.org/archive/html/qemu-devel/2021-09/msg00388.html | patch mailing list third party advisory |
| https://lists.debian.org/debian-lts-announce/2022/04/msg00002.html | third party advisory mailing list |
| https://security.netapp.com/advisory/ntap-20220425-0004/ | third party advisory |
| https://security.gentoo.org/glsa/202208-27 | third party advisory vendor advisory |
| https://lists.debian.org/debian-lts-announce/2022/09/msg00008.html | third party advisory mailing list |