OpenSSL is an Open Source toolkit implementing the Secure Sockets Layer (SSL v2/v3) and Transport Layer Security (TLS v1) as well as a general purpose cryptography library.
It was discovered that OpenSSL allow malicious servers to send very large primes to a client during DH(E) based TLS handshakes.
A remote attacker, by sending large prime to client during DH(E) TLS handshake, could possibly cause a Denial of Service condition.
There is no known workaround at this time.
All OpenSSL users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=dev-libs/openssl-1.0.2o-r6"