CVE-2017-12869 in SimpleSAMLphp
Summary
by MITRE
The multiauth module in SimpleSAMLphp 1.14.13 and earlier allows remote attackers to bypass authentication context restrictions and use an authentication source defined in config/authsources.php via vectors related to improper validation of user input.
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Analysis
by VulDB Data Team • 12/27/2022
The vulnerability identified as CVE-2017-12869 resides within the multiauth module of SimpleSAMLphp version 1.14.13 and earlier releases, presenting a critical security flaw that enables remote attackers to circumvent authentication context restrictions. This issue fundamentally undermines the authentication security model by allowing unauthorized access through improper validation of user input. SimpleSAMLphp serves as a widely adopted identity and access management solution that facilitates single sign-on and federation protocols, making this vulnerability particularly dangerous in environments relying on proper authentication controls.
The technical flaw manifests in the multiauth module's inadequate validation of user input parameters, specifically when processing authentication sources defined in the config/authsources.php configuration file. Attackers can exploit this weakness by crafting malicious input that bypasses the intended authentication context restrictions, effectively allowing them to utilize any authentication source configured in the system regardless of the user's actual authentication state or privileges. This improper input validation creates a pathway for privilege escalation and unauthorized system access, as the module fails to properly verify the legitimacy of authentication source selections during multi-factor authentication workflows.
The operational impact of this vulnerability extends beyond simple authentication bypass, as it can lead to complete system compromise when exploited in conjunction with other attack vectors. Organizations using SimpleSAMLphp for identity federation and authentication services face significant risk of unauthorized access to protected resources, user data breaches, and potential lateral movement within network environments. The vulnerability affects the core authentication mechanisms that protect sensitive applications and services, making it particularly dangerous in enterprise environments where proper access controls are paramount for security posture maintenance.
Mitigation strategies for CVE-2017-12869 should prioritize immediate patching of affected SimpleSAMLphp installations to version 1.14.14 or later, which contains the necessary fixes for the input validation issues. Organizations should also implement network segmentation and access controls to limit exposure of SimpleSAMLphp instances to untrusted networks, while monitoring for suspicious authentication attempts that may indicate exploitation attempts. Security teams should conduct comprehensive audits of authentication source configurations to ensure proper access controls and implement additional logging mechanisms to detect unauthorized authentication source usage. This vulnerability aligns with CWE-20, which addresses improper input validation, and maps to ATT&CK technique T1078 for valid accounts and T1566 for credential harvesting, emphasizing the need for robust authentication controls and monitoring.
The broader implications of this vulnerability highlight the critical importance of proper input validation in authentication modules, particularly in identity management systems that serve as central points of access control. Organizations should implement regular security assessments of their identity infrastructure, maintain up-to-date vulnerability management processes, and ensure that authentication modules receive proper security review and testing before deployment in production environments. The incident underscores the necessity of following security best practices such as principle of least privilege, input sanitization, and comprehensive testing of authentication workflows to prevent similar vulnerabilities from compromising system security.