CVE-2018-1305 in Instant Messaging Server
Summary
by MITRE
Security constraints defined by annotations of Servlets in Apache Tomcat 9.0.0.M1 to 9.0.4, 8.5.0 to 8.5.27, 8.0.0.RC1 to 8.0.49 and 7.0.0 to 7.0.84 were only applied once a Servlet had been loaded. Because security constraints defined in this way apply to the URL pattern and any URLs below that point, it was possible - depending on the order Servlets were loaded - for some security constraints not to be applied. This could have exposed resources to users who were not authorised to access them.
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Analysis
by VulDB Data Team • 08/09/2024
The vulnerability described in CVE-2018-1305 represents a critical authorization bypass issue within the Apache Tomcat web server implementation that affects multiple versions including 9.0.0.M1 through 9.0.4, 8.5.0 through 8.5.27, 8.0.0.RC1 through 8.0.49, and 7.0.0 through 7.0.84. This flaw stems from the improper application of security constraints that are defined through servlet annotations, creating a scenario where access controls are inconsistently enforced based on servlet loading order rather than being uniformly applied across all relevant URL patterns.
The technical nature of this vulnerability lies in how Tomcat processes security constraints defined through annotations such as WebServlet, WebInitParam, and related security annotations. When servlets are loaded dynamically during runtime, the security constraints that should apply to specific URL patterns and their sub-paths are only enforced after the servlet has been loaded into memory. This creates a race condition where the security framework fails to properly validate access rights for all URL patterns that should be protected by the defined constraints, particularly when servlets are loaded in different orders during application startup or deployment.
The operational impact of this vulnerability is significant as it allows unauthorized users to access protected resources that should only be available to authenticated and authorized personnel. This occurs because security constraints are not consistently applied across all URL patterns, enabling attackers to potentially bypass access controls when they can influence the order in which servlets are loaded. The vulnerability specifically affects applications that rely on annotation-based security configurations and can result in data exposure, privilege escalation, and unauthorized access to sensitive functionality within web applications hosted on affected Tomcat versions.
This vulnerability aligns with CWE-284 which describes improper access control issues, and relates to ATT&CK technique T1078 which covers valid accounts and T1566 which covers credential harvesting. The flaw demonstrates how improper implementation of security controls during component loading can create persistent access violations. Organizations using Tomcat versions within the affected ranges should immediately apply security patches and updates provided by Apache to ensure proper enforcement of security constraints regardless of servlet loading order. Additionally, administrators should review their application deployment configurations to minimize the risk of exploitation through servlet loading order manipulation and consider implementing additional access control layers as defensive measures against potential exploitation of this authorization bypass vulnerability.
The root cause of this issue demonstrates a fundamental flaw in how Tomcat's security framework handles dynamic loading of servlet components with security annotations, where the security enforcement mechanism is not properly synchronized with the servlet lifecycle management process. This architectural weakness allows for inconsistent security policy enforcement and creates an attack surface where the order of component initialization directly impacts the security posture of the application server.