libssh Server-Side Identity Authentication Bypass Vulnerability (CVE-2018-10933)Threat Alert

libssh Server-Side Identity Authentication Bypass Vulnerability (CVE-2018-10933)Threat Alert

October 23, 2018 | Adeline Zhang

Overview

On October 16, local time, libssh officially released an update to fix the server-side identity authentication bypass vulnerability (CVE-2018-10933) existing in libssh 0.6 and later versions. 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.

CVSS V3.0 base score: 9.8

CVSS vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)

Reference link:

https://www.libssh.org/2018/10/16/libssh-0-8-4-and-0-7-6-security-and-bugfix-release/

Affected Versions

  • libssh version >= 0.6
  • libssh version < 0.8.4
  • libssh version < 0.7.6

Unaffected Versions

  • libssh version = 0.8.4, 0.7.6

Solution

libssh has released unaffected versions. Affected users are advised to upgrade their products as soon as possible. The new unaffected versions libssh 0.0.4 and 0.7.6 can be downloaded from the following link: https://www.libssh.org/files/

Statement

This advisory is only used to describe a potential risk. NSFOCUS does not provide any commitment or promise on this advisory. NSFOCUS and the author will not bear any liability for any direct and/or indirect consequences and losses caused by transmitting and/or using this advisory. NSFOCUS reserves all the rights to modify and interpret this advisory. Please include this statement paragraph when reproducing or transferring this advisory. Do not modify this advisory, add/delete any information to/from it, or use this advisory for commercial purposes without permission from NSFOCUS.

About NSFOCUS

NSFOCUS IB is a wholly owned subsidiary of NSFOCUS, an enterprise application and network security provider, with operations in the Americas, Europe, the Middle East, Southeast Asia and Japan. NSFOCUS IB has a proven track record of combatting the increasingly complex cyber threat landscape through the construction and implementation of multi-layered defense systems. The company’s Intelligent Hybrid Security strategy utilizes both cloud and on-premises security platforms, built on a foundation of real-time global threat intelligence, to provide unified, multi-layer protection from advanced cyber threats.

For more information about NSFOCUS, please visit:

https://www.nsfocusglobal.com

NSFOCUS, NSFOCUS IB, and NSFOCUS, INC. are trademarks or registered trademarks of NSFOCUS, Inc. All other names and trademarks are property of their respective firms.