Intermediate TLS compatibility

The TLS protocol is used to provide privacy and data integrity between two or more communicating computer applications. When secured by TLS, connections between a client and a server have one or more of the following properties:-

1. The connection is private
2. The identity of parties can be authenticated
3. The connection is reliable

Transportation layer came from Secure Socket Layer. A careful configuration of TLS will provide additional privacy-related properties like forwarding secrecy, prevent discloser of encryption keys etc.

There are many applications that don’t need compatibility with Windows XP clients but still needs to support a wide range of clients. For handling this situation, this type of configuration is recommended. This fix is compatible with Firefox 1, Chrome 1, IE 7, Opera 5 and Safari 1.

Impact

The impact include:-

• Renegotiation attack
• Downgrade attacks like Logjam and FREAK
• Cross-platform attacks like DROWN
• BEAST attack
• Breach attacks
• POODLE attacks

Mitigation / Precaution

This vulnerability can be fixed by:-

• Changing to intermediate compatibility certificates if the users are still using Firefox 1, Chrome 1, IE 7, Opera 5 and Safari 1.

Written by

Rejah Rehim

Co-founder, Director

Rejah brings more than 12 years of industry experience in Information Technology. He is a fervent security enthusiast and serves as a Project Leader at OWASP Foundation, and Commander (Hon.) at Kerala Police. He has authored two books titled “Effective Python Penetration Testing” and “Python Penetration Testing Cookbook” and is the creator of 9 Mozilla add-ons.