#VU28557 Man-in-the-Middle (MitM) attack in GnuTLS - CVE-2020-13777
Published: June 4, 2020 / Updated: July 15, 2020
Vulnerability identifier: #VU28557
Vulnerability risk: Medium
CVSSv4.0: CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:P/U:Green
CVE-ID: CVE-2020-13777
CWE-ID: CWE-300
Exploitation vector: Adjecent network
Exploit availability:
Public exploit is available
Vulnerable software:
GnuTLS
GnuTLS
Software vendor:
GnuTLS
GnuTLS
Description
The vulnerability allows a remote attacker to perform Man-in-the-Middle (MitM) attack.
The vulnerability exists due to regression, introduced into the TLS protocol implementation that caused the TLS server to not securely construct a session ticket encryption key considering the application supplied secret. A remote attacker can bypass authentication in TLS 1.3 and recover previous conversations in TLS 1.2
Remediation
Install updates from vendor's website.