OpenSSL -- Client DoS due to large DH parameter

The OpenSSL project reports:

During key agreement in a TLS handshake using a DH(E) based
ciphersuite a malicious server can send a very large prime value
to the client. This will cause the client to spend an unreasonably
long period of time generating a key for this prime resulting in a
hang until the client has finished. This could be exploited in a
Denial Of Service attack.