CVE-2008-6658 in Simple Machines
Summary
by MITRE
Directory traversal vulnerability in index.php in Simple Machines Forum (SMF) 1.0 before 1.0.15 and 1.1 before 1.1.7 allows remote authenticated administrators to install packages from arbitrary directories via a .. (dot dot) in the package parameter during an install2 action, as demonstrated by a predictable package filename in attachments/ that was uploaded through a post2 action to index.php.
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Analysis
by VulDB Data Team • 11/10/2024
The vulnerability CVE-2008-6658 represents a directory traversal flaw in Simple Machines Forum versions prior to 1.0.15 and 1.1.7, specifically within the index.php file during package installation operations. This issue affects authenticated administrator accounts and demonstrates a critical security weakness in the forum's package management system. The vulnerability allows attackers with administrative privileges to manipulate file paths through the package parameter, enabling them to install malicious packages from arbitrary directories on the server filesystem. The flaw exploits the lack of proper input validation and path sanitization during the install2 action, which is part of the forum's package installation workflow.
The technical implementation of this vulnerability occurs when administrators perform package installation operations through the index.php script. During the install2 action, the application processes the package parameter without adequately validating or sanitizing directory traversal sequences such as .. (dot dot). This allows an authenticated administrator to specify package paths that include directory traversal components, effectively bypassing normal file access restrictions. The vulnerability is particularly dangerous because it leverages the existing administrative privileges of legitimate users, making it difficult to detect and distinguish from authorized activities. Attackers can exploit this by uploading a malicious package file to the predictable path attachments/ through the post2 action, then using the directory traversal technique to install the package from that location.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it enables attackers to potentially execute arbitrary code on the affected server. Since the package installation process typically involves executing PHP code from the uploaded packages, an attacker could install malicious code that compromises the entire server infrastructure. The vulnerability creates a persistent threat vector that could allow for data exfiltration, server compromise, or further lateral movement within the network. The fact that the vulnerability requires only authenticated administrator access makes it particularly concerning, as it can be exploited by insiders or through compromised administrative credentials. The predictable nature of the attachments/ directory path makes exploitation more straightforward, as attackers do not need to guess directory structures.
Organizations should implement multiple layers of defense to mitigate this vulnerability, including immediate patching of affected SMF installations to versions 1.0.15 or 1.1.7 and later. Access controls should be strictly enforced to limit administrative privileges to only necessary personnel, and regular security audits should be conducted to identify unauthorized administrative access. The vulnerability aligns with CWE-22 Directory Traversal and is categorized under the ATT&CK technique T1059 Command and Scripting Interpreter, as it allows for arbitrary code execution through package installation processes. Network monitoring should be enhanced to detect unusual package installation activities, particularly from administrative accounts. Additionally, input validation should be strengthened to reject any path traversal sequences in file operations, and the principle of least privilege should be enforced to minimize the potential impact of compromised administrative accounts.