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.
[
{
"target": {
"function": "virtio_net_receive_rcu",
"file": "hw/net/virtio-net.c"
},
"id": "CVE-2021-3748-63a59022",
"signature_version": "v1",
"signature_type": "Function",
"deprecated": false,
"digest": {
"length": 2573.0,
"function_hash": "14770436477810317024841570451115134811"
},
"source": "https://github.com/qemu/qemu/commit/bedd7e93d01961fcb16a97ae45d93acf357e11f6"
},
{
"target": {
"file": "hw/net/virtio-net.c"
},
"id": "CVE-2021-3748-b289847e",
"signature_version": "v1",
"signature_type": "Line",
"deprecated": false,
"digest": {
"threshold": 0.9,
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},
"source": "https://github.com/qemu/qemu/commit/bedd7e93d01961fcb16a97ae45d93acf357e11f6"
}
]