CVE-2018-6009 in Yii Framework
Summary
by MITRE
In Yii Framework 2.x before 2.0.14, the switchIdentity function in web/User.php did not regenerate the CSRF token upon a change of identity.
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Analysis
by VulDB Data Team • 02/02/2023
The vulnerability identified as CVE-2018-6009 affects the Yii Framework 2.x version prior to 2.0.14 and specifically targets the web/User.php component's switchIdentity function. This flaw represents a significant security weakness that undermines the framework's built-in protection mechanisms designed to prevent cross-site request forgery attacks. The issue occurs when an application user switches their identity within the framework, such as when an administrator logs in as a different user or when a user session is hijacked and subsequently changed. The core problem lies in the function's failure to regenerate the CSRF token, which is a critical security measure that ensures requests originate from legitimate users and prevents malicious actors from exploiting session management vulnerabilities.
The technical implementation of this vulnerability stems from the improper handling of session security tokens during identity transitions within the Yii framework's authentication system. When the switchIdentity function executes, it should automatically invalidate and regenerate the CSRF token to prevent potential exploitation by attackers who might attempt to reuse stale tokens from previous user sessions. This failure creates a window of opportunity for attackers to perform unauthorized actions using tokens that were generated under different user contexts. The vulnerability directly relates to CWE-352, which categorizes Cross-Site Request Forgery (CSRF) weaknesses, and demonstrates poor implementation of session management practices that violate fundamental security principles. The flaw essentially allows for session hijacking scenarios where an attacker could potentially execute actions as a different user without proper authentication.
The operational impact of this vulnerability extends beyond simple session management issues and could enable attackers to perform privilege escalation attacks, unauthorized transactions, or data manipulation within applications built on the Yii framework. When an application undergoes identity switching, particularly in administrative contexts, the absence of CSRF token regeneration creates a persistent security risk that could be exploited by malicious actors. This vulnerability is particularly concerning in applications where users can switch between different roles or accounts, as it provides attackers with a mechanism to maintain access to privileged functions even after legitimate identity changes have occurred. The flaw affects the integrity of the authentication system and undermines the trust model that applications rely upon for secure user management and session handling.
Organizations utilizing Yii Framework 2.x versions prior to 2.0.14 should immediately implement mitigations to address this vulnerability. The primary recommended solution involves upgrading to version 2.0.14 or later, which contains the necessary patches to ensure proper CSRF token regeneration during identity switching operations. Additionally, developers should review their application code to verify that no custom implementations of the switchIdentity function exist that might perpetuate this vulnerability. Security teams should conduct comprehensive vulnerability assessments to identify all applications built on affected framework versions and ensure proper patch management protocols are in place. The remediation process should also include monitoring for potential exploitation attempts and implementing additional security controls such as enhanced session management policies, regular token rotation, and comprehensive logging of identity switching events to detect suspicious activities. This vulnerability demonstrates the critical importance of maintaining up-to-date security frameworks and the potential consequences of failing to address known security flaws in web application development environments.