CVE-2006-5565 in MD-Pro
Summary
by MITRE
CRLF injection vulnerability in MAXdev MD-Pro 1.0.76 allows remote attackers to inject arbitrary HTTP headers via a CRLF sequence in the (1) name, (2) file, (3) module, and (4) func parameters in (a) index.php; and the (5) file parameter in (b) modules.php. NOTE: the provenance of this information is unknown; the details are obtained from third party information.
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Analysis
by VulDB Data Team • 04/25/2026
The CVE-2006-5565 vulnerability represents a critical CRLF (Carriage Return Line Feed) injection flaw discovered in MAXdev MD-Pro version 1.0.76, a web application framework that was widely used in the mid-2000s for content management and web development. This vulnerability resides in the application's handling of user-supplied input parameters within two primary script files: index.php and modules.php. The flaw specifically affects four distinct parameters in index.php - name, file, module, and func - while also impacting the file parameter in modules.php, making it particularly dangerous as it spans multiple entry points within the application's request processing pipeline.
The technical implementation of this vulnerability stems from inadequate input validation and sanitization within the MAXdev MD-Pro framework. When user-provided data is directly incorporated into HTTP response headers without proper encoding or filtering, attackers can inject malicious CRLF sequences that break out of the intended header context. This occurs because the application fails to properly escape or validate special characters in user input before using them in HTTP header construction. The vulnerability aligns with CWE-113, which specifically addresses "Improper Neutralization of CRLF Sequences in HTTP Headers" and represents a classic example of how insufficient input sanitization can lead to header injection attacks. The flaw operates at the application layer and leverages the fundamental weakness in HTTP protocol handling where CRLF sequences can be used to manipulate response headers.
The operational impact of this vulnerability is severe and multifaceted, potentially enabling attackers to perform various malicious activities including HTTP response splitting, session hijacking, cross-site scripting attacks, and cache poisoning. An attacker could inject malicious headers to redirect users to phishing sites, manipulate browser behavior, or even inject content that appears to come from the legitimate web server. The vulnerability is particularly concerning because it affects core application parameters that are commonly used in web applications, providing attackers with multiple attack vectors to exploit the same underlying flaw. This makes the vulnerability highly attractive to threat actors as it requires minimal effort to achieve significant impact, aligning with ATT&CK technique T1190 for "Exploit Public-Facing Application" and potentially T1566 for "Phishing" if used to redirect users to malicious sites.
Mitigation strategies for this vulnerability require immediate attention and should include comprehensive input validation and sanitization across all user-supplied parameters within the affected application components. The most effective approach involves implementing strict character filtering to prevent CRLF sequences from being processed in HTTP header contexts, along with proper encoding of user input before any header construction occurs. Organizations should also consider implementing web application firewalls that can detect and block CRLF injection attempts, while conducting thorough code reviews to identify similar patterns in other application components. Additionally, upgrading to a supported version of the MAXdev MD-Pro framework or migrating to a more modern and secure content management system would provide permanent resolution to this vulnerability, as the original framework is no longer maintained and likely contains additional undiscovered security flaws. The vulnerability demonstrates the critical importance of input validation in web applications and serves as a reminder of how legacy systems can harbor dangerous security weaknesses that persist long after their initial deployment.