ID CVE-2018-10933
Summary A vulnerability was found in libssh's server-side state machine before versions 0.7.6 and 0.8.4. A malicious client could create channels without first performing authentication, resulting in unauthorized access.
References
Vulnerable Configurations
  • Libssh 0.6.0
    cpe:2.3:a:libssh:libssh:0.6.0
  • Libssh 0.6.1
    cpe:2.3:a:libssh:libssh:0.6.1
  • Libssh 0.6.2
    cpe:2.3:a:libssh:libssh:0.6.2
  • Libssh 0.6.3
    cpe:2.3:a:libssh:libssh:0.6.3
  • Libssh 0.6.4
    cpe:2.3:a:libssh:libssh:0.6.4
  • Libssh 0.6.5
    cpe:2.3:a:libssh:libssh:0.6.5
  • Libssh 0.7.0
    cpe:2.3:a:libssh:libssh:0.7.0
  • Libssh 0.7.1
    cpe:2.3:a:libssh:libssh:0.7.1
  • Libssh 0.7.2
    cpe:2.3:a:libssh:libssh:0.7.2
  • Libssh 0.7.3
    cpe:2.3:a:libssh:libssh:0.7.3
  • Libssh 0.7.4
    cpe:2.3:a:libssh:libssh:0.7.4
  • Libssh 0.7.5
    cpe:2.3:a:libssh:libssh:0.7.5
  • Libssh 0.8.0
    cpe:2.3:a:libssh:libssh:0.8.0
  • Libssh 0.8.1
    cpe:2.3:a:libssh:libssh:0.8.1
  • Libssh 0.8.2
    cpe:2.3:a:libssh:libssh:0.8.2
  • Libssh 0.8.3
    cpe:2.3:a:libssh:libssh:0.8.3
  • Canonical Ubuntu Linux 14.04 LTS (Long-Term Support)
    cpe:2.3:o:canonical:ubuntu_linux:14.04:-:-:-:lts
  • Canonical Ubuntu Linux 16.04 LTS (Long-Term Support)
    cpe:2.3:o:canonical:ubuntu_linux:16.04:-:-:-:lts
  • Canonical Ubuntu Linux 18.04 LTS Edition
    cpe:2.3:o:canonical:ubuntu_linux:18.04:-:-:-:lts
  • Canonical Ubuntu Linux 18.10
    cpe:2.3:o:canonical:ubuntu_linux:18.10
  • Debian Linux 8.0 (Jessie)
    cpe:2.3:o:debian:debian_linux:8.0
  • Debian Linux 9.0
    cpe:2.3:o:debian:debian_linux:9.0
  • Red Hat Enterprise Linux (RHEL) 7.0 (7)
    cpe:2.3:o:redhat:enterprise_linux:7.0
  • cpe:2.3:a:netapp:oncommand_workflow_automation
    cpe:2.3:a:netapp:oncommand_workflow_automation
  • cpe:2.3:a:netapp:snapcenter
    cpe:2.3:a:netapp:snapcenter
  • cpe:2.3:a:netapp:storage_automation_store
    cpe:2.3:a:netapp:storage_automation_store
  • Oracle MySQL Workbench 8.0.13
    cpe:2.3:a:oracle:mysql_workbench:8.0.13
CVSS
Base: 6.4
Impact:
Exploitability:
CWE CWE-287
CAPEC
  • Authentication Abuse
    An attacker obtains unauthorized access to an application, service or device either through knowledge of the inherent weaknesses of an authentication mechanism, or by exploiting a flaw in the authentication scheme's implementation. In such an attack an authentication mechanism is functioning but a carefully controlled sequence of events causes the mechanism to grant access to the attacker. This attack may exploit assumptions made by the target's authentication procedures, such as assumptions regarding trust relationships or assumptions regarding the generation of secret values. This attack differs from Authentication Bypass attacks in that Authentication Abuse allows the attacker to be certified as a valid user through illegitimate means, while Authentication Bypass allows the user to access protected material without ever being certified as an authenticated user. This attack does not rely on prior sessions established by successfully authenticating users, as relied upon for the "Exploitation of Session Variables, Resource IDs and other Trusted Credentials" attack patterns.
  • Exploiting Trust in Client (aka Make the Client Invisible)
    An attack of this type exploits a programs' vulnerabilities in client/server communication channel authentication and data integrity. It leverages the implicit trust a server places in the client, or more importantly, that which the server believes is the client. An attacker executes this type of attack by placing themselves in the communication channel between client and server such that communication directly to the server is possible where the server believes it is communicating only with a valid client. There are numerous variations of this type of attack.
  • Utilizing REST's Trust in the System Resource to Register Man in the Middle
    This attack utilizes a REST(REpresentational State Transfer)-style applications' trust in the system resources and environment to place man in the middle once SSL is terminated. Rest applications premise is that they leverage existing infrastructure to deliver web services functionality. An example of this is a Rest application that uses HTTP Get methods and receives a HTTP response with an XML document. These Rest style web services are deployed on existing infrastructure such as Apache and IIS web servers with no SOAP stack required. Unfortunately from a security standpoint, there frequently is no interoperable identity security mechanism deployed, so Rest developers often fall back to SSL to deliver security. In large data centers, SSL is typically terminated at the edge of the network - at the firewall, load balancer, or router. Once the SSL is terminated the HTTP request is in the clear (unless developers have hashed or encrypted the values, but this is rare). The attacker can utilize a sniffer such as Wireshark to snapshot the credentials, such as username and password that are passed in the clear once SSL is terminated. Once the attacker gathers these credentials, they can submit requests to the web service provider just as authorized user do. There is not typically an authentication on the client side, beyond what is passed in the request itself so once this is compromised, then this is generally sufficient to compromise the service's authentication scheme.
  • Man in the Middle Attack
    This type of attack targets the communication between two components (typically client and server). The attacker places himself in the communication channel between the two components. Whenever one component attempts to communicate with the other (data flow, authentication challenges, etc.), the data first goes to the attacker, who has the opportunity to observe or alter it, and it is then passed on to the other component as if it was never intercepted. This interposition is transparent leaving the two compromised components unaware of the potential corruption or leakage of their communications. The potential for Man-in-the-Middle attacks yields an implicit lack of trust in communication or identify between two components.
exploit-db via4
  • id EDB-ID:46307
    last seen 2019-02-03
    modified 2018-10-20
    published 2018-10-20
    reporter Exploit-DB
    source https://www.exploit-db.com/download/46307
    title LibSSH 0.7.6 / 0.8.4 - Unauthorized Access
  • description libSSH - Authentication Bypass. CVE-2018-10933. Remote exploit for Linux platform
    file exploits/linux/remote/45638.py
    id EDB-ID:45638
    last seen 2018-11-27
    modified 2018-10-18
    platform linux
    port
    published 2018-10-18
    reporter Exploit-DB
    source https://old.exploit-db.com/download/45638/
    title libSSH - Authentication Bypass
    type remote
metasploit via4
description This module exploits an authentication bypass in libssh server code where a USERAUTH_SUCCESS message is sent in place of the expected USERAUTH_REQUEST message. libssh versions 0.6.0 through 0.7.5 and 0.8.0 through 0.8.3 are vulnerable. Note that this module's success depends on whether the server code can trigger the correct (shell/exec) callbacks despite only the state machine's authenticated state being set. Therefore, you may or may not get a shell if the server requires additional code paths to be followed.
id MSF:AUXILIARY/SCANNER/SSH/LIBSSH_AUTH_BYPASS
last seen 2019-03-21
modified 2019-03-05
published 2018-10-17
reliability Normal
reporter Rapid7
source https://github.com/rapid7/metasploit-framework/blob/master/modules/auxiliary/scanner/ssh/libssh_auth_bypass.rb
title libssh Authentication Bypass Scanner
nessus via4
  • NASL family Misc.
    NASL id LIBSSH_0_8_4_REMOTE.NASL
    description The remote ssh server is vulnerable to an authentication bypass. An attacker can bypass authentication by presenting SSH2_MSG_USERAUTH_SUCCESS message in place of the SSH2_MSG_USERAUTH_REQUEST method that normally would initiate authentication. Note: This vulnerability was disclosed in a libssh advisory but has also been observed as applicable to other applications and software packages.
    last seen 2019-02-21
    modified 2019-02-07
    plugin id 118154
    published 2018-10-17
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=118154
    title SSH Protocol Authentication Bypass (Remote Exploit Check)
  • NASL family Ubuntu Local Security Checks
    NASL id UBUNTU_USN-3795-1.NASL
    description Peter Winter-Smith discovered that libssh incorrectly handled authentication when being used as a server. A remote attacker could use this issue to bypass authentication without any credentials. Note that Tenable Network Security has extracted the preceding description block directly from the Ubuntu security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
    last seen 2019-02-21
    modified 2018-12-01
    plugin id 118200
    published 2018-10-18
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=118200
    title Ubuntu 14.04 LTS / 16.04 LTS / 18.04 LTS : libssh vulnerability (USN-3795-1)
  • NASL family SuSE Local Security Checks
    NASL id OPENSUSE-2018-1180.NASL
    description This update for libssh fixes the following issues : - CVE-2018-10933: Fixed a server mode authentication bypass (bsc#1108020). This update was imported from the SUSE:SLE-15:Update update project.
    last seen 2019-02-21
    modified 2018-10-26
    plugin id 118191
    published 2018-10-18
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=118191
    title openSUSE Security Update : libssh (openSUSE-2018-1180)
  • NASL family SuSE Local Security Checks
    NASL id OPENSUSE-2018-1207.NASL
    description This update for libssh fixes the following security issue : - CVE-2018-10933: Fixed a server mode authentication bypass (boo#1108020). This update was imported from the SUSE:SLE-12:Update update project.
    last seen 2019-02-21
    modified 2018-10-26
    plugin id 118250
    published 2018-10-22
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=118250
    title openSUSE Security Update : libssh (openSUSE-2018-1207)
  • NASL family Debian Local Security Checks
    NASL id DEBIAN_DLA-1548.NASL
    description Peter Winter-Smith of NCC Group discovered that libssh, a tiny C SSH library, contains an authentication bypass vulnerability in the server code. An attacker can take advantage of this flaw to successfully authenticate without any credentials 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. For Debian 8 'Jessie', this problem has been fixed in version 0.6.3-4+deb8u3. We recommend that you upgrade your libssh packages. NOTE: Tenable Network Security has extracted the preceding description block directly from the DLA security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
    last seen 2019-02-21
    modified 2018-10-26
    plugin id 118214
    published 2018-10-19
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=118214
    title Debian DLA-1548-1 : libssh security update
  • NASL family Fedora Local Security Checks
    NASL id FEDORA_2018-BCA1C1AB49.NASL
    description Update to version 0.7.6 to address CVE-2018-10933 Note that Tenable Network Security has extracted the preceding description block directly from the Fedora update system website. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
    last seen 2019-02-21
    modified 2018-10-26
    plugin id 118243
    published 2018-10-22
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=118243
    title Fedora 27 : libssh (2018-bca1c1ab49)
  • NASL family SuSE Local Security Checks
    NASL id SUSE_SU-2018-3162-1.NASL
    description This update for libssh fixes the following issues : CVE-2018-10933: Fixed a server mode authentication bypass (bsc#1108020). Note that Tenable Network Security has extracted the preceding description block directly from the SUSE security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
    last seen 2019-02-21
    modified 2019-01-02
    plugin id 120131
    published 2019-01-02
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=120131
    title SUSE SLED15 / SLES15 Security Update : libssh (SUSE-SU-2018:3162-1)
  • NASL family Fedora Local Security Checks
    NASL id FEDORA_2018-C08CD808D3.NASL
    description Update to version 0.8.4 to address CVE-2018-10933 Note that Tenable Network Security has extracted the preceding description block directly from the Fedora update system website. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
    last seen 2019-02-21
    modified 2019-01-03
    plugin id 120760
    published 2019-01-03
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=120760
    title Fedora 28 : libssh (2018-c08cd808d3)
  • NASL family Misc.
    NASL id LIBSSH_0_8_4.NASL
    description According to its banner version, the remote libssh based server is vulnerable to an authentication bypass. An attacker can bypass authentication by presenting a SSH2_MSG_USERAUTH_SUCCESS message in place of the SSH2_MSG_USERAUTH_REQUEST method that normally would initiate authentication. Note that Nessus did not actually test for the flaw but instead has relied on the version in the libssh banner so this may be a false positive.
    last seen 2019-02-21
    modified 2018-11-07
    plugin id 118155
    published 2018-10-17
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=118155
    title libssh 0.6.x / 0.7.x < 0.7.6 / 0.8.x < 0.8.4 Authentication Bypass (Remote Version Check)
  • NASL family Fedora Local Security Checks
    NASL id FEDORA_2018-6B390CEB36.NASL
    description Update to version 0.8.4 to fix CVE-2018-10933 Note that Tenable Network Security has extracted the preceding description block directly from the Fedora update system website. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
    last seen 2019-02-21
    modified 2019-01-03
    plugin id 120502
    published 2019-01-03
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=120502
    title Fedora 29 : libssh (2018-6b390ceb36)
  • NASL family Ubuntu Local Security Checks
    NASL id UBUNTU_USN-3795-2.NASL
    description USN-3795-1 fixed a vulnerability in libssh. This update provides the corresponding update for Ubuntu 18.10. Original advisory details : Peter Winter-Smith discovered that libssh incorrectly handled authentication when being used as a server. A remote attacker could use this issue to bypass authentication without any credentials. Note that Tenable Network Security has extracted the preceding description block directly from the Ubuntu security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
    last seen 2019-02-21
    modified 2018-12-01
    plugin id 118325
    published 2018-10-23
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=118325
    title Ubuntu 18.10 : libssh vulnerability (USN-3795-2)
  • NASL family FreeBSD Local Security Checks
    NASL id FREEBSD_PKG_2383767CD22411E89623A4BADB2F4699.NASL
    description gladiac reports : 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 authentciate without any credentials.
    last seen 2019-02-21
    modified 2018-11-10
    plugin id 118182
    published 2018-10-18
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=118182
    title FreeBSD : libssh -- authentication bypass vulnerability (2383767c-d224-11e8-9623-a4badb2f4699)
  • NASL family Debian Local Security Checks
    NASL id DEBIAN_DSA-4322.NASL
    description Peter Winter-Smith of NCC Group discovered that libssh, a tiny C SSH library, contains an authentication bypass vulnerability in the server code. An attacker can take advantage of this flaw to successfully authenticate without any credentials 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.
    last seen 2019-02-21
    modified 2018-11-13
    plugin id 118180
    published 2018-10-18
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=118180
    title Debian DSA-4322-1 : libssh - security update
  • NASL family SuSE Local Security Checks
    NASL id SUSE_SU-2018-3253-1.NASL
    description This update for libssh fixes the following issues : Security issue fixed : CVE-2018-10933: Fixed a server mode authentication bypass (bsc#1108020). Non security issue fixed: Fix popd syntax to be compatible with newer versions of the bash shell. Note that Tenable Network Security has extracted the preceding description block directly from the SUSE security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
    last seen 2019-02-21
    modified 2018-12-01
    plugin id 118306
    published 2018-10-22
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=118306
    title SUSE SLED12 Security Update : libssh (SUSE-SU-2018:3253-1)
  • NASL family Slackware Local Security Checks
    NASL id SLACKWARE_SSA_2018-289-01.NASL
    description New libssh packages are available for Slackware 14.0, 14.1, 14.2, and -current to fix a security issue.
    last seen 2018-10-27
    modified 2018-10-26
    plugin id 118168
    published 2018-10-17
    reporter Tenable
    source https://www.tenable.com/plugins/index.php?view=single&id=118168
    title Slackware 14.0 / 14.1 / 14.2 / current : libssh (SSA:2018-289-01)
packetstorm via4
refmap via4
bid 105677
confirm
debian DSA-4322
exploit-db 45638
mlist [debian-lts-announce] 20181018 [SECURITY] [DLA 1548-1] libssh security update
ubuntu
  • USN-3795-1
  • USN-3795-2
saint via4
bid 105677
description libssh authentication bypass
id misc_lib_libsshver
title libssh_auth_bypass
type remote
the hacker news via4
id THN:964B5C1CA23FD1DE427C22FC59CD0AEC
last seen 2018-10-17
modified 2018-10-17
published 2018-10-17
reporter The Hacker News
source https://thehackernews.com/2018/10/libssh-ssh-protocol-library.html
title LibSSH Flaw Allows Hackers to Take Over Servers Without Password
Last major update 17-10-2018 - 08:29
Published 17-10-2018 - 08:29
Last modified 25-04-2019 - 09:41
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