CVE-2008-3715 in FlexCMS
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in inc-core-admin-editor-previouscolorsjs.php in the FlexCMS 2.5 and earlier, when register_globals is enabled, allows remote attackers to inject arbitrary web script or HTML via the PreviousColorsString parameter.
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Analysis
by VulDB Data Team • 06/28/2025
The vulnerability identified as CVE-2008-3715 represents a critical cross-site scripting flaw within the FlexCMS content management system version 2.5 and earlier. This vulnerability specifically affects systems where the PHP configuration parameter register_globals is enabled, creating a dangerous condition that allows remote attackers to execute malicious code through web scripts or HTML injection. The affected file inc-core-admin-editor-previouscolorsjs.php serves as the entry point for this particular security weakness, demonstrating how seemingly minor components can become significant attack vectors in web applications.
The technical flaw stems from improper input validation and output encoding within the FlexCMS administration interface. When register_globals is enabled, PHP automatically creates global variables from request parameters, eliminating the need for explicit variable declarations. This configuration creates a dangerous scenario where user-supplied data from the PreviousColorsString parameter can be directly incorporated into the application's output without proper sanitization. The vulnerability operates under CWE-79, which classifies cross-site scripting as a weakness where untrusted data is embedded into web pages viewed by other users. Attackers can exploit this by crafting malicious payloads that, when processed by the vulnerable system, execute in the context of other users' browsers, potentially leading to session hijacking, credential theft, or further exploitation.
The operational impact of this vulnerability extends beyond simple script injection, as it provides attackers with persistent access to the affected system's administrative functions. When successful, the XSS attack can enable attackers to manipulate the CMS interface, potentially gaining unauthorized access to sensitive content, modifying website data, or even installing backdoors for continued access. The vulnerability's exploitation requires minimal effort from attackers, as they only need to submit malicious input through the PreviousColorsString parameter, making it particularly dangerous in environments where legitimate users interact with the CMS administration interface. This flaw also aligns with ATT&CK technique T1566, which covers social engineering tactics that involve manipulating users into executing malicious code through web-based attacks.
Mitigation strategies for CVE-2008-3715 must address both the immediate vulnerability and underlying configuration issues. The primary recommendation involves disabling register_globals in PHP configuration settings, as this parameter fundamentally undermines web application security by creating automatic global variables from user input. Additionally, implementing proper input validation and output encoding mechanisms should be enforced throughout the application, particularly for parameters that are directly used in dynamic content generation. The FlexCMS development team should implement proper parameter sanitization techniques and ensure that all user-supplied data is properly escaped before being rendered in web pages. Organizations should also consider implementing content security policies and regular security audits to detect similar vulnerabilities in other components of their web applications. The vulnerability demonstrates the critical importance of secure coding practices and proper configuration management in preventing widespread exploitation of web-based applications.