CVE-2007-1394 in Flat Chat
Summary
by MITRE
Direct static code injection vulnerability in startsession.php in Flat Chat 2.0 allows remote attackers to execute arbitrary PHP code via the Chat Name field, which is inserted into online.txt and included by users.php. NOTE: some of these details are obtained from third party information.
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Analysis
by VulDB Data Team • 08/26/2024
The vulnerability described in CVE-2007-1394 represents a critical direct static code injection flaw within the Flat Chat 2.0 web application. This vulnerability exists in the startsession.php script where user input from the Chat Name field is directly incorporated into the online.txt file without proper sanitization or validation. The flaw occurs because the application fails to implement adequate input filtering mechanisms, allowing malicious actors to inject arbitrary PHP code that gets executed when the online.txt file is included by users.php. This creates a classic code injection vulnerability that can be exploited remotely, making it particularly dangerous for web applications that process user-supplied data.
The technical exploitation of this vulnerability follows a specific attack pattern where an attacker submits malicious PHP code through the Chat Name field during session initialization. The submitted code is then written to the online.txt file, which serves as a temporary storage mechanism for active chat session data. When the users.php script processes this data and includes the online.txt file, the malicious PHP code gets executed within the context of the web server. This type of vulnerability falls under CWE-94, which specifically addresses "Improper Control of Generation of Code ('Code Injection')" and represents a fundamental failure in input validation and output encoding practices. The vulnerability is classified as a remote code execution vulnerability because attackers can exploit it without requiring local system access or authentication.
The operational impact of this vulnerability is severe and multifaceted, affecting system integrity, confidentiality, and availability. Successful exploitation allows attackers to execute arbitrary commands on the target server, potentially leading to complete system compromise, data theft, or service disruption. The vulnerability affects the entire Flat Chat 2.0 application ecosystem, as any user who interacts with the chat system could become a vector for code injection. Organizations running this vulnerable software face significant risk of unauthorized access, data breaches, and potential lateral movement within their network infrastructure. The vulnerability's remote nature means that attackers can exploit it from anywhere on the internet, making it particularly dangerous for publicly accessible web applications. From an attack framework perspective, this vulnerability aligns with ATT&CK technique T1059.007 for "Command and Scripting Interpreter: PowerShell" and T1059.001 for "Command and Scripting Interpreter: Unix Shell" when considering the potential for command execution.
Mitigation strategies for this vulnerability must address both immediate remediation and long-term architectural improvements. The primary fix involves implementing proper input validation and sanitization mechanisms that prevent malicious code from being accepted or processed in the Chat Name field. This includes using allowlists of permitted characters, implementing proper escaping mechanisms, and ensuring that user input cannot be interpreted as executable code. Organizations should also consider implementing proper file inclusion practices by using secure methods that prevent arbitrary file inclusion attacks. Additional defensive measures include regular security audits, input validation testing, and implementing web application firewalls to detect and block suspicious input patterns. The vulnerability serves as a prime example of why proper secure coding practices are essential, particularly when handling user input in web applications, and demonstrates the importance of following secure development lifecycle principles to prevent such critical flaws from being introduced into production systems.