CVE-2021-20257: Debian Linux

Medium severity, CVSS 6.5. EPSS: 0.4% chance of exploitation in the next 30 days.

An infinite loop flaw was found in the e1000 NIC emulator of the QEMU. This issue occurs while processing transmits (tx) descriptors in process_tx_desc if various descriptor fields are initialized with invalid values. This flaw allows a guest to consume CPU cycles on the host, resulting in a denial of service. The highest threat from this vulnerability is to system availability.

Affected products

• Debian Debian Linux: version 10.0 only
• Fedoraproject Fedora: version 33 only
• Qemu Qemu: before 6.2.0 (fixed in 6.2.0)
• Red Hat Codeready Linux Builder: affected versions not specified
• Red Hat Enterprise Linux: version 6.0 only; version 8.0 only
• Red Hat Enterprise Linux For IBM Z Systems: version 8.0 only
• Red Hat Enterprise Linux For Power Little Endian: version 8.0 only
• Red Hat Openstack Platform: version 10.0 only; version 13.0 only

Published 2022-03-16. Last modified 2026-06-17.