CVE-2002-1757 in PHProjekt
Summary
by MITRE
PHProjekt 2.0 through 3.1 relies on the $PHP_SELF variable for authentication, which allows remote attackers to bypass authentication for scripts via a request to a .php file with "sms" in the URL, which is included in the PATH_INFO portion of the $PHP_SELF variable, as demonstrated using "mail_send.php/sms".
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Analysis
by VulDB Data Team • 09/01/2025
The vulnerability described in CVE-2002-1757 represents a critical authentication bypass flaw in PHProjekt versions 2.0 through 3.1 that stems from improper handling of the PHP_SELF variable. This issue falls under the category of weak authentication mechanisms and demonstrates how web applications can inadvertently expose themselves to unauthorized access through flawed input validation and variable processing. The vulnerability specifically exploits the way PHP applications handle the PATH_INFO component of URLs, creating a pathway for attackers to circumvent security controls without proper credentials.
The technical flaw occurs when the PHProjekt application uses the $PHP_SELF variable to determine which scripts require authentication. The $PHP_SELF variable contains the filename of the currently executing script, including any PATH_INFO that may be present in the URL. When an attacker crafts a request to a .php file with "sms" appearing in the PATH_INFO portion of the URL, the application fails to properly validate or sanitize this input. This allows the malicious PATH_INFO component to be included in the $PHP_SELF variable, which the application then uses to determine access control. The vulnerability is particularly insidious because it leverages legitimate PHP functionality in an unintended manner to bypass security checks.
The operational impact of this vulnerability is significant as it enables remote attackers to gain unauthorized access to protected application functionality without requiring valid credentials. An attacker can simply construct a URL that includes "sms" within the PATH_INFO portion and access restricted areas of the application. This bypass affects the entire authentication system and could potentially allow access to sensitive data, administrative functions, or other protected resources within the PHProjekt application. The attack vector is particularly dangerous because it requires minimal privileges and can be executed through standard web browser requests, making it accessible to virtually any attacker with basic web browsing capabilities.
This vulnerability aligns with CWE-285, which addresses improper authorization issues in software applications, and demonstrates how insecure input handling can lead to authentication bypass scenarios. From an ATT&CK framework perspective, this represents a privilege escalation technique that leverages application weaknesses in input validation and authentication mechanisms. The vulnerability also reflects poor secure coding practices related to parameter validation and input sanitization, which are fundamental requirements in secure software development. Organizations should implement proper input validation and avoid relying on potentially manipulable server variables like $PHP_SELF for critical security decisions. The recommended mitigations include implementing strict URL parameter validation, using proper authentication checks that do not depend on PATH_INFO or similar variables, and ensuring that all application logic properly sanitizes and validates user input before processing. Additionally, upgrading to patched versions of PHProjekt or implementing proper access control measures can effectively address this vulnerability.