A stack based buffer overflow was found in the virtio-net device of QEMU. This issue occurs when flushing TX in the virtionetflushtx function if guest features VIRTIONETFHASHREPORT, VIRTIOFVERSION1 and VIRTIONETFMRGRXBUF are enabled. This could allow a malicious user to overwrite local variables allocated on the stack. Specifically, the out_sg
variable could be used to read a part of process memory and send it to the wire, causing an information leak.