SSL_peek() hang on empty record (CVE-2016-6305)

Summary

OpenSSL 1.1.0 SSL/TLS will hang during a call to SSL_peek() if the peer sends an empty record. This could be exploited by a malicious peer in a Denial Of Service attack.

OpenSSL 1.1.0 users should upgrade to 1.1.0a

This issue was reported to OpenSSL on 10th September 2016 by Alex Gaynor. The fix was developed by Matt Caswell of the OpenSSL development team.