CVE-2006-0202 in PHP Toolkit
Summary
by MITRE
Dave Nielsen and Patrick Breitenbach PayPal Web Services (aka PHP Toolkit) 0.50 and possibly earlier has (1) world-readable permissions for ipn/logs/ipn_success.txt, which allows local users to view sensitive information (payment data), and (2) world-writable permissions for ipn/logs, which allows local users to delete or replace payment data.
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Analysis
by VulDB Data Team • 07/31/2017
The vulnerability identified in CVE-2006-0202 affects the PayPal Web Services PHP Toolkit version 0.50 and potentially earlier releases, presenting critical security flaws in file permission configurations that expose sensitive payment information to unauthorized local users. This vulnerability resides within the toolkit's logging mechanism where the ipn/logs/ipn_success.txt file is configured with world-readable permissions, creating an information disclosure risk that allows any local user to access payment transaction data. The severity of this issue is compounded by the fact that the ipn/logs directory itself is configured with world-writable permissions, enabling local users to not only read sensitive payment information but also to modify or delete payment data entirely.
The technical flaw stems from improper file system permission settings within the PayPal PHP toolkit implementation, specifically targeting the Internet Payment Notification (IPN) logging functionality. When the toolkit processes payment notifications, it creates log files in the ipn/logs directory to record transaction success or failure information. The default configuration fails to establish appropriate access controls, leaving the ipn_success.txt file accessible to all system users and the containing directory writable by all users. This configuration violates fundamental security principles of least privilege and proper access control enforcement, creating a scenario where local users can exploit these misconfigurations to gain unauthorized access to payment processing data.
The operational impact of this vulnerability extends beyond simple information disclosure, encompassing potential data integrity violations and financial fraud opportunities. Local users with access to the system can exploit the world-readable permissions to extract sensitive payment information including transaction amounts, customer details, and payment identifiers. Additionally, the world-writable directory permissions create a more severe threat vector where malicious users could delete critical log files, potentially masking fraudulent activities or replacing legitimate payment records with forged data. This vulnerability directly affects the confidentiality, integrity, and availability of payment processing data, undermining the trust and security foundations of the payment processing system.
The security implications of this vulnerability align with CWE-732 and CWE-276, which address improper file permissions and inadequate access control mechanisms respectively. From an attack perspective, this vulnerability maps to ATT&CK techniques including T1005 (Data from Local System) and T1486 (Data Encrypted for Impact) where attackers can leverage local access to extract or modify payment data. The vulnerability also represents a failure in the principle of least privilege enforcement, where file access controls are not properly configured to restrict access to sensitive payment information. Organizations using this toolkit face significant risk of payment data exposure, potential fraud, and compliance violations under data protection regulations such as PCI DSS requirements for secure handling of payment card information.
Mitigation strategies should focus on immediate permission corrections where the ipn/logs/ipn_success.txt file must be configured with restrictive permissions limiting access to the web server user account only, typically using chmod 600 or equivalent access control mechanisms. The ipn/logs directory permissions should be adjusted to prevent world-writable access, typically implementing chmod 750 or similar restrictive settings. Additionally, organizations should implement regular security audits to verify proper file permissions, establish automated monitoring for unauthorized permission changes, and ensure that all payment processing components are configured with appropriate access controls. The toolkit should be updated to a secure version that properly implements access controls, and system administrators should conduct comprehensive reviews of all log file locations and their corresponding access permissions to prevent similar vulnerabilities in other components of the payment processing infrastructure.