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On August 24, QEMU released a security patch to fix a VM escape vulnerability (CVE-2020-14364) which is the result of an out-of-bounds read/write access issue in the USB emulator in QEMU. This vulnerability resides in ./hw/usb/core.c. When the program handles USB packets from a guest, this vulnerability is deemed to exist if USBDevice ‘setup_len’ exceeds its ‘data_buf[4096]’ in the do_token_in and do_token_out routines. An attacker could exploit this vulnerability to cause out-of-bounds read of the 0xffffffff contents following the heap, forcibly terminating the virtual process and realizing VM escape. An attacker with access to a VM operating system in the cloud environment could exploit this vulnerability to gain host privileges to target all tenant hosts within the resource pool that holds the VM. Worse still, the attacker, with his or her gained intranet privileges, could attack systems within the management domain. QEMU (short for quick emulator) is an analog processor written by Fabrice Bellard and others to distribute GPL-licensed source code. It is an underlying commercial component used by numerous cloud vendors. This vulnerability affects most cloud vendors that use OpenStack. Users are advised to take precautionary measures as soon as possible to fix this vulnerability.