CVE-2021-3416: Debian Linux

Medium severity, CVSS 6.0. EPSS: 0.5% chance of exploitation in the next 30 days.

A potential stack overflow via infinite loop issue was found in various NIC emulators of QEMU in versions up to and including 5.2.0. The issue occurs in loopback mode of a NIC wherein reentrant DMA checks get bypassed. A guest user/process may use this flaw to consume CPU cycles or crash the QEMU process on the host resulting in DoS scenario.

Affected products

• Debian Debian Linux: version 9.0 only; version 10.0 only
• Fedoraproject Fedora: version 33 only
• Qemu Qemu: up to and including 5.2.0
• Red Hat Enterprise Linux: version 6.0 only; version 7.0 only; version 8.0 only

Published 2021-03-18. Last modified 2026-06-17.