Description
The LOGJAM attack is a SSL/TLS vulnerability that allows attackers to intercept HTTPS connections between vulnerable clients and servers and force them to use 'export-grade' cryptography, which can then be decrypted or altered. This vulnerability alert is issued when a web site is found to support DH(E) export cipher suites, or non-export DHE cipher suites using either DH primes smaller than 1024 bits, or commonly used DH standard primes up to 1024 bits.
Remediation
Reconfigure the affected SSL/TLS server to disable support for any DHE_EXPORT suites, for DH primes smaller than 1024 bits, and for DH standard primes up to 1024 bits. Refer to the "Guide to Deploying Diffie-Hellman for TLS" for further guidance on how to configure affected systems accordingly.