CVE-2006-4315 in SSH
Summary
by MITRE
Unquoted Windows search path vulnerability in multiple SSH Tectia products, including Client/Server/Connector 5.0.0 and 5.0.1 and Client/Server before 4.4.5, and Manager 2.12 and earlier, when running on Windows, might allow local users to gain privileges via a malicious program file under "Program Files" or its subdirectories.
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Analysis
by VulDB Data Team • 08/02/2018
The vulnerability described in CVE-2006-4315 represents a critical security flaw in SSH Tectia products that affects multiple versions across different product lines including Client, Server, Connector, and Manager components. This issue specifically impacts Windows implementations where the software fails to properly handle quoted paths during the search process, creating a privilege escalation vector for local attackers. The vulnerability stems from the improper handling of environment variables and search paths that allow malicious programs to be executed with elevated privileges when placed in specific directories under the Program Files hierarchy. The root cause of this vulnerability aligns with CWE-428, which describes the improper handling of unquoted search paths, a well-documented weakness that has been consistently exploited in various Windows environments.
The technical exploitation of this vulnerability occurs when the SSH Tectia software searches for executable files in the Program Files directory and its subdirectories without properly quoting the search paths. This allows local attackers to place malicious executables in directories that are searched before the legitimate program files, effectively enabling privilege escalation attacks. When the system attempts to execute a program, it follows the search order and will execute the malicious file if it appears before the legitimate one in the path. This behavior directly violates the principle of least privilege and creates a dangerous condition where user-level processes can potentially elevate their privileges to system level. The vulnerability operates at the operating system level and leverages fundamental Windows path resolution mechanisms that have been historically problematic for many applications.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it provides attackers with a persistent foothold within the system that can be leveraged for further attacks. Local users who can write to the Program Files directory or its subdirectories can place malicious executables that will be executed with the privileges of the SSH Tectia service, potentially leading to complete system compromise. This vulnerability is particularly dangerous because it requires minimal privileges to exploit and can be combined with other attack vectors to create more sophisticated attacks. The vulnerability affects multiple versions of SSH Tectia products, making it widespread across various deployment scenarios and increasing the potential attack surface for organizations using these products. The impact is consistent with ATT&CK technique T1068, which describes the use of privilege escalation techniques through local system exploits.
Organizations should immediately implement several mitigation strategies to address this vulnerability. The most effective immediate fix involves applying the vendor patches released for the affected versions of SSH Tectia products, which typically include proper quoting of search paths and improved path resolution mechanisms. System administrators should also implement strict file system permissions to prevent unauthorized modifications to the Program Files directory structure, particularly for the affected SSH Tectia installation paths. Additionally, implementing application whitelisting policies can prevent the execution of unauthorized binaries even if they are placed in the vulnerable directories. The remediation process should include thorough security audits of all systems running affected SSH Tectia versions to identify and address any potential exploitation attempts. Regular monitoring of system logs for suspicious execution patterns and unauthorized file modifications should be implemented as part of ongoing security operations. Organizations should also consider implementing network segmentation and access controls to limit the potential impact of successful exploitation attempts, as the vulnerability can be leveraged to establish persistent access to the compromised systems.