Here are the description about the vulnerabilities:
Alternative chains certificate forgery (CVE-2015-1793). During certificate verification, OpenSSL (starting from version 1.0.1n and 1.0.2b) will attempt to find an alternative certificate chain if the first attempt to build such a chain fails. An error in the implementation of this logic can mean that an attacker could cause certain checks on untrusted certificates to be bypassed, such as the CA flag, enabling them to use a valid leaf certificate to act as a CA and "issue" an invalid certificate. This issue will impact any application that verifies certificates including SSL/TLS/DTLS clients and SSL/TLS/DTLS servers using client authentication. This issue affects OpenSSL versions 1.0.2c, 1.0.2b, 1.0.1n and 1.0.1o. This issue was reported to OpenSSL on 24th June 2015 by Adam Langley/David Benjamin (Google/BoringSSL). The fix was developed by the BoringSSL project.