libssh is a multiplatform C library implementing the SSHv2 protocol on client and server side.
It was discovered that libssh could crash when AES-CTR ciphers are used.
A remote attacker running a malicious client or server could possibly crash the counterpart implemented with libssh and cause a Denial of Service condition.
Disable AES-CTR ciphers. If you implement a server using libssh it is recommended to use a prefork model so each session runs in an own process.
All libssh users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=net-libs/libssh-0.9.4"