CVE-2008-4730 in phpMyID
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in MyID.php in phpMyID 0.9 allows remote attackers to inject arbitrary web script or HTML via the openid_trust_root parameter and an inconsistent openid_return_to parameter, which is not properly handled in an error message.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 10/13/2018
The vulnerability described in CVE-2008-4730 represents a classic cross-site scripting flaw within the phpMyID 0.9 authentication system. This issue manifests in the MyID.php script where improper input validation and sanitization creates an exploitable condition for remote attackers. The vulnerability specifically targets two parameters within the OpenID authentication flow: openid_trust_root and openid_return_to. These parameters are fundamental components of the OpenID protocol that establish trust relationships and return URLs for authentication responses. When these parameters contain malicious script code and are subsequently rendered in error messages without proper HTML escaping or encoding, the system becomes vulnerable to XSS attacks.
The technical exploitation of this vulnerability occurs through the manipulation of OpenID parameters during the authentication process. Attackers can craft malicious URLs with script payloads in either the openid_trust_root or openid_return_to fields, which are then processed by the MyID.php script. When the system encounters an error condition related to these parameters, it displays error messages containing the unsanitized input directly in the web response. This failure to properly escape or encode user-supplied data during error message generation creates the XSS vector. The vulnerability is particularly concerning because it leverages legitimate OpenID functionality to deliver malicious payloads, making it harder to detect and prevent through traditional security measures.
The operational impact of this vulnerability extends beyond simple script injection, as it can enable attackers to perform various malicious activities within the context of the vulnerable application. An attacker could potentially execute arbitrary JavaScript code in the victim's browser, leading to session hijacking, credential theft, or redirection to malicious sites. The vulnerability affects the authentication integrity of phpMyID 0.9, potentially compromising user sessions and undermining the security of database access controls. Given that phpMyID was designed for database management authentication, successful exploitation could lead to unauthorized database access or modification of sensitive information. The vulnerability also demonstrates a broader pattern of insufficient input validation that violates security best practices for web application development.
Mitigation strategies for this vulnerability should focus on implementing proper input sanitization and output encoding throughout the application's error handling mechanisms. The most effective approach involves sanitizing all user-supplied parameters before they are processed or displayed in error messages, specifically implementing HTML escaping for any data that might be rendered in web responses. Additionally, developers should adopt a principle of least privilege in parameter handling, validating input against expected formats and rejecting malformed or suspicious data. The fix should align with CWE-79 which specifically addresses cross-site scripting vulnerabilities through proper input validation and output encoding. Organizations should also consider implementing Content Security Policy headers to provide additional defense-in-depth against XSS attacks, though this represents a secondary mitigation rather than a primary fix. Regular security audits and input validation testing should be integrated into development processes to prevent similar vulnerabilities in future releases. The vulnerability underscores the importance of treating all user inputs as untrusted and applying consistent sanitization techniques across all application components, particularly those handling authentication protocols where trust relationships are established.