CVE-2020-11501

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.

CVSS 3.1

7.4CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

EPSS

3.4% chance of exploitation in the next 30 days; higher than 88% of CVEs (scores of 2026-10-25)

CWE

CWE-330

Published

2020-04-03

Modified

2026-10-14

Record from

the NVD, synced 2026-10-19

Affected

• canonical:ubuntu_linux
• debian:debian_linux
• fedoraproject:fedora
• gnu:gnutls
• opensuse:leap

References

• http://lists.opensuse.org/opensuse-security-announce/2020-04/msg00015.html
• https://gitlab.com/gnutls/gnutls/-/commit/5b595e8e52653f6c5726a4cdd8fddeb6e83804d2
• https://gitlab.com/gnutls/gnutls/-/issues/960
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ILMOWPKMTZAIMK5F32TUMO34XCABUCFJ/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WDYY3R4F5CUTFAMXH2C5NKYFVDEJLTT7/

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