CVE-2010-2945 in Slim Simple Login Manager
Summary
by MITRE
The default configuration of SLiM before 1.3.2 places ./ (dot slash) at the beginning of the default_path option, which might allow local users to gain privileges via a Trojan horse program in the current working directory, related to slim.conf and cfg.cpp.
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Analysis
by VulDB Data Team • 09/24/2021
The vulnerability identified as CVE-2010-2945 affects the SLiM (Simple Login Manager) authentication system version 1.3.1 and earlier, representing a critical privilege escalation flaw in the default configuration settings. This vulnerability stems from how SLiM handles the default_path option in its configuration file, specifically when the ./ (current directory) prefix is included at the beginning of the path specification. The flaw creates a dangerous environment where local attackers can exploit the system's trust in the current working directory to execute malicious code with elevated privileges. The vulnerability is particularly concerning because it directly impacts the login process and authentication mechanisms that are fundamental to system security.
The technical implementation of this vulnerability involves the insecure handling of path resolution within the slim.conf configuration file and the corresponding cfg.cpp source code implementation. When SLiM initializes with the default_path option containing the ./ prefix, it processes the path in a manner that does not properly sanitize or validate the current working directory. This allows an attacker to place a malicious Trojan horse program in the current working directory, which will then be executed with the privileges of the SLiM process. The flaw operates under the principle of path traversal and privilege escalation, where the system's default configuration creates an insecure execution environment. The vulnerability is classified as a weakness in the configuration management and path resolution mechanisms, which aligns with CWE-276, which addresses improper privileges and access control issues.
The operational impact of this vulnerability is severe as it enables local users to escalate their privileges from standard user level to root or administrative privileges without requiring any special authentication credentials. This privilege escalation occurs during the login process when SLiM attempts to execute programs from the configured default_path. Attackers can exploit this by placing malicious executables in directories that are part of the default_path, particularly those beginning with ./, thereby gaining unauthorized access to system resources. The vulnerability is particularly dangerous in multi-user environments where local access to a system could lead to complete system compromise, as it bypasses the normal authentication mechanisms and allows attackers to execute arbitrary code with elevated privileges.
The exploitation of this vulnerability can be mapped to several techniques described in the MITRE ATT&CK framework, specifically under privilege escalation techniques such as "Path Interception" and "Exploitation for Privilege Escalation." The vulnerability creates a persistent attack vector that allows for long-term system compromise, as the malicious programs placed in the current working directory will continue to be executed whenever the affected SLiM configuration is used. System administrators should consider implementing the principle of least privilege in their configurations and ensure that default_path settings do not include insecure path prefixes. The recommended mitigation involves updating to SLiM version 1.3.2 or later, which addresses the insecure default configuration, and manually reviewing the slim.conf file to remove the ./ prefix from default_path settings. Additionally, implementing proper file permissions and directory access controls can help prevent unauthorized modification of the current working directory where SLiM executes its programs.