Уязвимость сервера Network Block Device (NBD) эмулятора аппаратного обеспечения QEMU, позволяющая нарушителю вызвать отказ в обслуживании

A stack-based buffer overflow vulnerability was found in NBD server implementation in qemu before 2.11 allowing a client to request an export name of size up to 4096 bytes, which in fact should be limited to 256 bytes, causing an out-of-bounds stack write in the qemu process. If NBD server requires TLS, the attacker cannot trigger the buffer overflow without first successfully negotiating TLS.

The Network Block Device (NBD) server in Quick Emulator (QEMU) before 2.11 is vulnerable to a denial of service issue. It could occur if a client sent large option requests, making the server waste CPU time on reading up to 4GB per request. A client could use this flaw to keep the NBD server from serving other requests, resulting in DoS.