PT-2020-13675 · Gnu+7 · Gnutls+7

Published

2020-06-03

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Updated

2024-07-04

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CVE-2020-13777

CVSS v3.1

7.4

High

VectorAV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
Name of the Vulnerable Software and Affected Versions GnuTLS versions 3.6.4 through 3.6.14
Description The issue is related to incorrect cryptography used for encrypting a session ticket, leading to a loss of confidentiality in TLS 1.2 and an authentication bypass in TLS 1.3. This allows an attacker to resume a TLS 1.3 session without knowing the master key, enabling man-in-the-middle (MITM) attacks. The earliest affected version is 3.6.4 due to an error in a 2018-09-18 commit. Until the first key rotation, the TLS server always uses wrong data in place of an encryption key derived from an application.
Recommendations For GnuTLS versions 3.6.4 through 3.6.14, update to version 3.6.14 or later to resolve the issue. As a temporary workaround, consider restricting access to TLS 1.3 sessions or disabling session resumption until a patch is available. Avoid using the affected GnuTLS library for sensitive transactions until the issue is resolved.

Exploit

Fix

Use of a Broken Cryptographic Algorithm

Weakness Enumeration

Related Identifiers

ALT-PU-2020-2128
ALT-PU-2020-2159
CESA-2020_2637
CVE-2020-13777
DSA-4697-1
ELSA-2020-2637
MGASA-2020-0268
OPENSUSE-SU-2020:0790-1
OPENSUSE-SU-2020_0790-1
OPENSUSE-SU-2024:10801-1
RHSA-2020:2637
RHSA-2020:2638
RHSA-2020:2639
RHSA-2020_2637
SUSE-SU-2020:1584-1
SUSE-SU-2020_1584-1
USN-4384-1

Affected Products

Alt Linux
Centos
Gnutls
Linuxmint
Red Hat
Red Os
Suse
Ubuntu