gnutls: session resumption works without master key allowing MITM (CVE-2020-13777)
GnuTLS 3.6.x before 3.6.14 uses incorrect cryptography for encrypting a session ticket (a loss of confidentiality in TLS 1.2, and an authentication bypass in TLS 1.3). The earliest affected version is 3.6.4 (2018-09-24) because of 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.
Fixed In Version:
GnuTLS 3.6.14 or later versions.
References:
- https://gnutls.org/security-new.html#GNUTLS-SA-2020-06-03
- https://nvd.nist.gov/vuln/detail/CVE-2020-13777
Patches:
- https://gitlab.com/gnutls/gnutls/-/merge_requests/1275/diffs?commit_id=c2646aeee94e71cb15c90a3147cf3b5b0ca158ca
- https://gitlab.com/gnutls/gnutls/-/merge_requests/1275/diffs?commit_id=3d7fae761e65e9d0f16d7247ee8a464d4fe002da