ArchLinux: 201609-25: gnutls: certificate verification bypass
Summary
Incorrect length validation on gnutls's gnutls_ocsp_resp_check_crt method can allow an attacker to use a OCSP response for a different certificate (but from the same CA) to continue using a revoked certificate. This can happen if the serial from the revoked certificate is a prefix of the other one, and the additional bytes happen to be equal on the system doing the verification.
Resolution
Upgrade to 3.4.15-1.
# pacman -Syu "gnutls>=3.4.15-1"
The problem has been fixed upstream in version 3.4.15.
References
https://lists.gnupg.org/pipermail/gnutls-devel/2016-September/008146.html https://gitlab.com/gnutls/gnutls/-/commit/964632f37dfdfb914ebc5e49db4fa29af35b1de9 https://access.redhat.com/security/cve/CVE-2016-7444
Workaround
None.