system
Describe <CVE-2015-5894>.
user
What is <CVE-2015-5894>?
assistant
The X.509 certificate-trust implementation in Apple OS X before 10.11 does not recognize that the kSecRevocationRequirePositiveResponse flag implies a revocation-checking requirement, which makes it easier for man-in-the-middle attackers to spoof endpoints by leveraging access to a revoked certificate..