CVE-2020-11501: Canonical Ubuntu Linux

High severity, CVSS 7.4. EPSS: 3.4% chance of exploitation in the next 30 days.

GnuTLS 3.6.x before 3.6.13 uses incorrect cryptography for DTLS. The earliest affected version is 3.6.3 (2018-07-16) because of an error in a 2017-10-06 commit. The DTLS client always uses 32 '\0' bytes instead of a random value, and thus contributes no randomness to a DTLS negotiation. This breaks the security guarantees of the DTLS protocol.

Affected products

• Canonical Ubuntu Linux: version 19.10 only
• Debian Debian Linux: version 10.0 only
• Fedoraproject Fedora: version 31 only; version 32 only
• GNU Gnutls: from 3.6.3, before 3.6.13 (fixed in 3.6.13)
• Opensuse Leap: version 15.1 only

Published 2020-04-03. Last modified 2026-06-17.