CVE-2018-10933

Description

libssh versions 0.6 and above have an authentication bypass vulnerability in
the server code. By presenting the server an SSH2_MSG_USERAUTH_SUCCESS message
in place of the SSH2_MSG_USERAUTH_REQUEST message which the server would expect
to initiate authentication, the attacker could successfully authenticate without any credentials.

Patch Availability

Patches addressing the issue have been posted to:
<https://www.libssh.org/2018/10/16/libssh-0-8-4-and-0-7-6-security-and-bugfix-release/&gt;
libssh version 0.8.4 and libssh 0.7.6 have been released to address this issue.

Workaround

There is no workaround for this issue.

Credit

The bug was discovered by Peter Winter-Smith of NCC Group.
Patches are provided by the Anderson Toshiyuki Sasaki of Red Hat and the libssh team.

Recent assessments:

xFreed0m at March 13, 2020 9:49am UTC reported:

LibSSH isn’t common as other SSH server softwares and vulnerability is pretty dates so finding this in the wild won’t be a walk in the park.
Having said that, if adversaries will find this software installed with a vulnerable version, exploitation is extremely easy (multiple exploit exists in the internet) and usually will provided access from the external to the server while fully bypassing the authentication.
for example – <https://github.com/xFreed0m/CVE-2018-10933&gt;

Assessed Attacker Value: 4
Assessed Attacker Value: 4Assessed Attacker Value: 5