CVE-2020-29570: Debian Linux

Medium severity, CVSS 6.2. EPSS: 0.4% chance of exploitation in the next 30 days.

An issue was discovered in Xen through 4.14.x. Recording of the per-vCPU control block mapping maintained by Xen and that of pointers into the control block is reversed. The consumer assumes, seeing the former initialized, that the latter are also ready for use. Malicious or buggy guest kernels can mount a Denial of Service (DoS) attack affecting the entire system.

Affected products

• Debian Debian Linux: version 10.0 only
• Fedoraproject Fedora: version 32 only; version 33 only
• Xen Xen: from 4.4.0, up to and including 4.14.0

Published 2020-12-15. Last modified 2026-06-17.