ibssh versions 0.5.1 and above have a logical error in the handling of a SSH_MSG_NEWKEYS and SSH_MSG_KEXDH_REPLY package. A detected error did not set the session into the error state correctly and further processed the packet which leads to a null pointer dereference. This is the packet after the initial key exchange and doesn’t require authentication.
This could be used for a Denial of Service (DoS) attack. The bug was found and reported by Mariusz Ziulek from the Open Web Application Security Project (OWASP). https://www.libssh.org/2015/04/30/libssh-0-6-5-security-and-bugfix-release/ -- Andreas Schneider GPG-ID: CC014E3D www.cryptomilk.org [email protected]
