CVE-2006-4913 in E-friends
Summary
by MITRE
Directory traversal vulnerability in chat/getStartOptions.php in AlstraSoft E-friends 4.85 allows remote attackers to include arbitrary local files and possibly execute arbitrary code via a .. (dot dot) sequence and trailing null (%00) byte in the lang parameter, as demonstrated by injecting PHP code into a log file.
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Analysis
by VulDB Data Team • 07/21/2024
The vulnerability identified as CVE-2006-4913 represents a critical directory traversal flaw within the AlstraSoft E-friends 4.85 web application, specifically affecting the chat/getStartOptions.php script. This vulnerability falls under the category of CWE-22 - Improper Limitation of a Pathname to a Restricted Directory, which is a fundamental security weakness that allows attackers to manipulate file path resolution mechanisms. The flaw occurs when the application fails to properly validate or sanitize user input that is used to construct file paths, enabling unauthorized access to sensitive system resources.
The technical exploitation of this vulnerability relies on the manipulation of the lang parameter through a combination of directory traversal sequences and null byte injection. Attackers can craft malicious input containing .. (dot dot) sequences followed by a trailing null byte %00 to bypass directory restriction mechanisms. When the application processes this input without proper sanitization, it allows the attacker to traverse the filesystem hierarchy and access arbitrary local files that should otherwise be protected. The vulnerability becomes particularly dangerous when combined with the ability to inject PHP code into log files, as demonstrated in the exploit scenario.
The operational impact of this vulnerability extends beyond simple file disclosure to potentially enable remote code execution within the context of the web application. Once an attacker successfully exploits this directory traversal vulnerability, they can access sensitive configuration files, database credentials, application source code, and other system resources that may contain critical information. The injection of PHP code into log files creates a persistent backdoor mechanism that allows attackers to execute arbitrary commands on the server, effectively compromising the entire web application environment. This vulnerability directly maps to ATT&CK technique T1566.001 - Phishing: Spearphishing Attachment, as attackers can leverage this flaw to establish persistent access through manipulated file inclusion mechanisms.
The security implications of CVE-2006-4913 are particularly severe in web applications where user input is directly incorporated into file operations without proper validation. The vulnerability demonstrates a classic lack of input sanitization and output encoding practices that are fundamental to secure coding standards. Organizations running AlstraSoft E-friends 4.85 are at significant risk of complete system compromise, data exfiltration, and potential lateral movement within their network infrastructure. The combination of directory traversal and code execution capabilities makes this vulnerability highly attractive to attackers and represents a critical security gap that requires immediate remediation.
Mitigation strategies for this vulnerability must address both the immediate exploitation vector and the underlying architectural weaknesses. The most effective approach involves implementing strict input validation and sanitization for all user-supplied parameters, particularly those used in file path construction. Developers should employ whitelisting mechanisms that only permit known good values for language parameters, rather than accepting arbitrary input. Additionally, the application should implement proper path resolution functions that prevent directory traversal attempts, including the use of realpath() and basename() functions to normalize file paths. System administrators should also ensure that the web application runs with minimal required privileges and that proper access controls are implemented to limit the impact of any successful exploitation attempts. Regular security audits and code reviews should be conducted to identify similar vulnerabilities in other components of the application stack.