CVE-2004-1584 in WordPress
Summary
by MITRE
CRLF injection vulnerability in wp-login.php in WordPress 1.2 allows remote attackers to perform HTTP Response Splitting attacks to modify expected HTML content from the server via the text parameter.
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Analysis
by VulDB Data Team • 06/23/2025
The vulnerability identified as CVE-2004-1584 represents a critical CRLF injection flaw discovered in the wp-login.php file of WordPress version 1.2, which enables remote attackers to execute HTTP response splitting attacks. This security weakness arises from inadequate input validation and sanitization of user-supplied data within the authentication process, specifically targeting the text parameter that is processed during login operations. The flaw allows malicious actors to inject carriage return and line feed characters into HTTP response headers, thereby manipulating the server's response structure and potentially redirecting users to malicious websites or injecting unauthorized content into web pages.
The technical implementation of this vulnerability stems from the improper handling of user input in the WordPress authentication mechanism. When the text parameter is submitted through the login form, the application fails to properly sanitize or escape special characters including carriage return \r and line feed \n sequences. This lack of input validation creates an opening for attackers to inject malicious HTTP headers that can alter the intended response behavior of the web server. The vulnerability is particularly dangerous because it occurs during the authentication phase, which is a critical point where users trust the application to maintain secure and predictable behavior while processing their credentials and session management.
From an operational perspective, this vulnerability exposes WordPress installations to significant security risks including session hijacking, cross-site scripting attacks, and malicious redirection. Attackers can exploit the CRLF injection to inject arbitrary HTTP headers such as Location headers that redirect users to phishing sites or inject malicious content into the response stream. The impact extends beyond simple content modification as it can potentially enable more sophisticated attacks like cookie manipulation, where attackers can set malicious cookies that persist across user sessions. This vulnerability directly violates the principle of least privilege and can compromise the integrity of the entire authentication system, undermining user trust and potentially leading to complete account compromise.
The vulnerability aligns with CWE-113, which specifically addresses improper neutralization of CRLF sequences in HTTP headers, and represents a classic example of HTTP response splitting attacks that have been documented in various security frameworks including the OWASP Top Ten. From an ATT&CK perspective, this vulnerability maps to T1190 - Exploit Public-Facing Application, where adversaries leverage weaknesses in web applications to gain unauthorized access or manipulate application behavior. The attack surface is particularly concerning as it targets the login functionality, which is one of the most frequently accessed components of any web application, making it an attractive target for attackers seeking persistent access to user accounts and system resources.
Mitigation strategies for this vulnerability include immediate patching of WordPress installations to versions that properly sanitize input parameters and validate user-supplied data before processing. Organizations should implement comprehensive input validation mechanisms that filter or escape special characters including CRLF sequences in all user-facing parameters. Network-level protections such as web application firewalls can help detect and block malicious CRLF injection attempts, while proper header sanitization at the application level should be enforced to prevent header injection attacks. Regular security auditing of web applications should include testing for similar injection vulnerabilities, and organizations should maintain up-to-date security patches and implement defense-in-depth strategies to protect against such critical flaws that can compromise entire authentication systems.