In the GnuTLS library, which is used by default in many Debian packages, including the APT package manager and many utilities, (), allowing the resumption of a previously halted TLS session without knowledge of the session key. Practically, this vulnerability can be exploited for MITM attacks.
The vulnerability is caused by incorrect construction of the session ticket key — the TLS server did not bind the encryption session key to the value provided by the application. Until the first rotation of the key, the TLS server continues to use incorrect data instead of the encryption key obtained from the application when generating session keys, allowing an attacker to bypass authentication in TLS 1.3 and resume past sessions in TLS 1.2.
Sérülékenység in release 3.6.14, which also resolves issues with the handling of cross-signed certificates that emerged after the expiration of the AddTrust root certificate. The problem manifests starting from release 3.6.4 (2018-09-24). In distributions, the vulnerability has been addressed in , , , , , , (RHEL 6 and 7 ).
Forrás: opennet.ru
