CVE-2007-5072 in Simple PHP Blog
Summary
by MITRE
Multiple cross-site scripting (XSS) vulnerabilities in Simple PHP Blog (SPHPBlog) before 0.5.1, when register_globals is enabled, allow remote attackers to inject arbitrary web script or HTML via certain user_colors array parameters to certain user_style.php files under themes/, as demonstrated by the user_colors[bg_color] parameter.
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Analysis
by VulDB Data Team • 11/03/2017
The vulnerability identified as CVE-2007-5072 represents a critical cross-site scripting flaw in Simple PHP Blog versions prior to 0.5.1 that specifically exploits the insecure handling of user input when the register_globals PHP configuration directive is enabled. This vulnerability resides within the themes directory structure, particularly in user_style.php files that process user_colors array parameters, with the background color parameter serving as the primary attack vector. The flaw demonstrates a classic input validation and output encoding deficiency that enables malicious actors to inject arbitrary web scripts or HTML content into the application's response.
The technical exploitation of this vulnerability occurs through the manipulation of the user_colors[bg_color] parameter which is processed without proper sanitization or encoding. When register_globals is enabled, PHP automatically creates global variables from GET, POST, and cookie data, creating an environment where user-supplied input can directly influence the application's behavior. The vulnerability stems from the application's failure to properly validate and sanitize the user_colors array parameters before incorporating them into dynamically generated HTML output. This creates a condition where malicious input can be executed within the context of other users' browsers, allowing attackers to perform session hijacking, defacement, or other malicious activities.
The operational impact of this vulnerability extends beyond simple data theft or defacement, as it provides attackers with persistent access to the application's user base. Once exploited, the XSS payload can be stored and executed whenever affected users view pages that utilize the compromised theme parameters, creating a vector for widespread exploitation. The vulnerability's persistence is particularly concerning as it can be leveraged for session theft, credential harvesting, or redirection to malicious sites. From a cybersecurity perspective, this vulnerability aligns with CWE-79 which specifically addresses cross-site scripting flaws, and represents a failure to implement proper input validation and output encoding as recommended in the OWASP Top Ten security controls.
Mitigation strategies for CVE-2007-5072 require both immediate and long-term approaches to address the underlying security issues. The most effective immediate solution involves upgrading to Simple PHP Blog version 0.5.1 or later, which contains the necessary patches to properly sanitize user input. Additionally, administrators should disable the register_globals directive in their PHP configurations, as this setting fundamentally undermines application security by creating global variables from user input. Implementing proper input validation and output encoding practices, including the use of htmlspecialchars() functions when rendering user-supplied data, would prevent the exploitation of similar vulnerabilities. Organizations should also consider implementing content security policies and regular security audits to identify and remediate similar weaknesses in their web applications. The vulnerability demonstrates the critical importance of following secure coding practices and adhering to security standards such as those defined in the MITRE ATT&CK framework for web application security.