It was found that in the OpenSSL address implementation the hard coded 1024 bit DH p parameter was not prime. The effective cryptographic strength of a key exchange using these parameters was weaker than the one one could get by using a prime p, making easier for eavesdropper to recover the shared secret from a key exchange that uses them. Affected versions are 1.7.3.0 and 2.0.0-b8. http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-2217