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.
A flaw in the ssl3_take_mac function can result in a NULL pointer dereference.
A remote attacker could send a specially crafted TLS handshake, resulting in a Denial of Service condition.
There is no known workaround at this time.
All OpenSSL 1.0.1 users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=dev-libs/openssl-1.0.1f"