CVE-2018-10933 in MySQL Workbench
Summary
by MITRE
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.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 06/21/2024
The vulnerability identified as CVE-2018-10933 represents a critical flaw in the libssh library's server-side state machine implementation that affected versions prior to 0.7.6 and 0.8.4. This security weakness stems from an insufficient validation mechanism within the SSH protocol handshake process, specifically during the channel creation phase. The flaw allows an attacker to establish communication channels without completing the required authentication procedures, fundamentally undermining the security model of the SSH protocol.
The technical root cause of this vulnerability lies in the improper state transition handling within libssh's server implementation where the authentication check is bypassed during channel establishment. When a malicious client connects to an affected ssh server, it can proceed directly to channel creation without providing valid credentials, effectively circumventing the authentication layer. This occurs due to a missing validation step that should verify the client's authenticated status before allowing channel operations to commence. The vulnerability is classified as a state machine flaw that violates the expected protocol sequence and creates an authentication bypass condition.
The operational impact of CVE-2018-10933 is severe and far-reaching across numerous systems that rely on libssh for secure remote access. Attackers exploiting this vulnerability can gain unauthorized access to systems, potentially leading to complete compromise of the affected infrastructure. The vulnerability affects any application or service using vulnerable versions of libssh, including but not limited to SSH servers, network management tools, and automated deployment systems. This flaw particularly impacts organizations using embedded systems, network appliances, and custom applications that integrate libssh functionality, as these environments often lack proper network segmentation and monitoring controls.
Organizations should prioritize immediate remediation by upgrading to libssh versions 0.7.6 or 0.8.4, which contain the necessary patches to address the authentication bypass mechanism. System administrators should conduct comprehensive inventory checks to identify all systems utilizing vulnerable libssh versions and implement network monitoring to detect suspicious authentication patterns. The vulnerability aligns with CWE-284, which addresses improper access control in software implementations, and corresponds to ATT&CK technique T1078.004 for valid accounts and T1021.004 for SSH. Additionally, implementing proper intrusion detection systems, network segmentation, and regular security audits can help mitigate potential exploitation attempts and provide defense-in-depth measures against similar authentication bypass vulnerabilities.