CVE-2021-3409: Debian Linux

Medium severity, CVSS 5.7. EPSS: 0.5% chance of exploitation in the next 30 days.

The patch for CVE-2020-17380/CVE-2020-25085 was found to be ineffective, thus making QEMU vulnerable to the out-of-bounds read/write access issues previously found in the SDHCI controller emulation code. This flaw allows a malicious privileged guest to crash the QEMU process on the host, resulting in a denial of service or potential code execution. QEMU up to (including) 5.2.0 is affected by this.

Affected products

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

Published 2021-03-23. Last modified 2026-06-17.