CVE-2005-1951 in osCommerce
Summary
by MITRE
Multiple HTTP Response Splitting vulnerabilities in osCommerce 2.2 Milestone 2 and earlier allow remote attackers to spoof web content and poison web caches via hex-encoded CRLF ("%0d%0a") sequences in the (1) products_id or (2) pid parameter to index.php or (3) goto parameter to banner.php.
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Analysis
by VulDB Data Team • 09/05/2025
The vulnerability described in CVE-2005-1951 represents a critical HTTP response splitting flaw affecting osCommerce versions 2.2 Milestone 2 and earlier. This vulnerability resides in the web application's handling of user-supplied input parameters within HTTP requests, specifically targeting the products_id, pid, and goto parameters across different script endpoints. The flaw enables malicious actors to inject malicious content into HTTP responses by exploiting the application's insufficient input validation mechanisms. When the application processes these parameters without proper sanitization, it allows attackers to insert carriage return and line feed characters that can manipulate the HTTP response headers, creating a condition where subsequent content becomes part of the HTTP response rather than being treated as separate HTTP messages.
The technical exploitation of this vulnerability follows a specific pattern where attackers utilize hex-encoded CRLF sequences (%0d%0a) to inject malicious content into the application's response handling. When the osCommerce application processes parameters containing these encoded sequences, it fails to properly sanitize or encode the input before incorporating it into HTTP response headers or content. This vulnerability specifically affects the index.php script when processing products_id or pid parameters, and the banner.php script when handling the goto parameter. The flaw occurs because the application does not implement proper input validation or output encoding for user-supplied data that might be used in HTTP response construction, creating a pathway for attackers to manipulate the HTTP response structure and inject malicious content.
The operational impact of this vulnerability extends beyond simple content manipulation, as it enables sophisticated attacks such as cross-site scripting, cache poisoning, and web content spoofing. Attackers can leverage this vulnerability to inject malicious JavaScript code or redirect users to fraudulent websites, potentially compromising user sessions and stealing sensitive information. The vulnerability particularly affects web cache poisoning scenarios where malicious content injected into the response can be cached by intermediate proxies or CDN services, affecting multiple users simultaneously. This type of vulnerability can be exploited to create persistent security issues that may remain undetected for extended periods, as the malicious content becomes embedded within cached responses and can be served to unsuspecting users without requiring further exploitation of the original vulnerability.
Mitigation strategies for CVE-2005-1951 should focus on implementing proper input validation and output encoding mechanisms throughout the application's codebase. The most effective approach involves sanitizing all user-supplied input parameters before they are processed or included in HTTP responses, particularly those parameters that might influence response headers or content. Implementing proper parameter validation using regular expressions or input whitelisting techniques can prevent the injection of malicious CRLF sequences. Additionally, applications should employ proper HTTP response encoding for all user-controllable parameters and implement Content Security Policy headers to prevent the execution of malicious scripts. This vulnerability aligns with CWE-113, which describes improper neutralization of CRLF sequences in HTTP headers, and represents a classic example of how insufficient input validation can lead to serious security implications. Organizations should also consider implementing web application firewalls and monitoring systems that can detect and block suspicious CRLF injection patterns, as this vulnerability can be effectively mitigated through proper application hardening and defensive programming practices. The ATT&CK framework categorizes this type of vulnerability under T1555, which covers credentials from password storage repositories, as the ability to manipulate HTTP responses can lead to session hijacking and other credential-related attacks.