CVE-2019-20175: Qemu

High severity, CVSS 7.5. EPSS: 3.4% chance of exploitation in the next 30 days.

An issue was discovered in ide_dma_cb() in hw/ide/core.c in QEMU 2.4.0 through 4.2.0. The guest system can crash the QEMU process in the host system via a special SCSI_IOCTL_SEND_COMMAND. It hits an assertion that implies that the size of successful DMA transfers there must be a multiple of 512 (the size of a sector). NOTE: a member of the QEMU security team disputes the significance of this issue because a "privileged guest user has many ways to cause similar DoS effect, without triggering this assert.

Affected products

• Qemu Qemu: from 2.4.0, up to and including 4.2.0

Published 2019-12-31. Last modified 2026-06-17.