CVE-2001-0995 in PHProjekt
Summary
by MITRE
PHProjekt before 2.4a allows remote attackers to perform actions as other PHProjekt users by modifying the ID number in an HTTP request to PHProjekt CGI programs.
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Analysis
by VulDB Data Team • 09/30/2025
The vulnerability identified as CVE-2001-0995 represents a critical authorization flaw in PHProjekt versions prior to 2.4a, specifically affecting the web-based project management application's CGI programs. This issue stems from insufficient input validation and improper session management mechanisms that allow malicious actors to manipulate HTTP requests and assume the identities of other users within the system. The vulnerability manifests when attackers modify the ID number parameter within HTTP requests sent to PHProjekt CGI applications, effectively bypassing the application's user authentication and authorization controls.
This technical flaw constitutes a classic case of insecure direct object reference vulnerability, which is categorized under CWE-639 as "Authorization Bypass Through User-Controlled Key." The vulnerability exists because PHProjekt relies on predictable identifiers and does not properly verify whether the authenticated user has authorization to perform actions on the specified object or user account. When an attacker manipulates the ID parameter in requests, the application fails to validate the ownership or permission relationships, allowing arbitrary privilege escalation.
The operational impact of this vulnerability is significant and multifaceted. Attackers can exploit this weakness to access confidential project data, modify user accounts, manipulate project timelines, alter task assignments, and potentially gain administrative privileges within the PHProjekt environment. This unauthorized access capability enables malicious actors to conduct data theft, disrupt project workflows, and compromise the integrity of project management information. The vulnerability also provides a pathway for persistent access, as attackers can maintain control over compromised accounts long after the initial exploitation attempt.
From an attack methodology perspective, this vulnerability aligns with techniques described in the MITRE ATT&CK framework under the T1078 credential access tactic and T1566 initial access technique. The attack requires minimal sophistication as it involves simple HTTP request manipulation, making it accessible to attackers with basic web application exploitation knowledge. The vulnerability's impact extends beyond immediate data compromise to include potential lateral movement within the organization's project management infrastructure, especially if PHProjekt is integrated with other systems or used as a central collaboration platform.
The recommended mitigations for this vulnerability include immediate upgrading to PHProjekt version 2.4a or later, where the authorization mechanisms have been properly implemented. Organizations should also implement proper input validation and parameter sanitization measures to prevent direct object reference manipulation. Additional protective measures include implementing role-based access controls, establishing robust session management protocols, and conducting regular security assessments of web applications to identify similar authorization bypass vulnerabilities. Network segmentation and monitoring of suspicious HTTP request patterns can also help detect exploitation attempts and limit the potential damage from such attacks.