CVE-2016-0714 in Communications
Summary
by MITRE
The session-persistence implementation in Apache Tomcat 6.x before 6.0.45, 7.x before 7.0.68, 8.x before 8.0.31, and 9.x before 9.0.0.M2 mishandles session attributes, which allows remote authenticated users to bypass intended SecurityManager restrictions and execute arbitrary code in a privileged context via a web application that places a crafted object in a session.
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Analysis
by VulDB Data Team • 04/09/2023
The vulnerability identified as CVE-2016-0714 represents a critical security flaw in Apache Tomcat's session persistence mechanism that affects multiple major versions including 6.x through 9.x. This issue stems from improper handling of session attributes during the persistence process, creating a pathway for authenticated attackers to circumvent security controls and execute malicious code within the privileged context of the web application server. The vulnerability specifically targets the session management subsystem where session data is serialized and stored, enabling attackers to inject crafted objects that can be deserialized later, leading to arbitrary code execution. The flaw is particularly dangerous because it operates at the session persistence layer, meaning that any authenticated user with access to session management functionality can potentially exploit this weakness without requiring additional privileges or complex attack vectors.
The technical implementation of this vulnerability resides in the session serialization and deserialization processes within Tomcat's session persistence framework. When session attributes are stored and later retrieved, the system uses Java serialization mechanisms to convert objects into byte streams for storage. The flaw occurs when the session persistence implementation fails to properly validate or sanitize session attributes before serialization, allowing malicious objects to be stored in session data. These objects can then be deserialized during subsequent requests, executing arbitrary code with the privileges of the Tomcat process. This vulnerability aligns with CWE-502 which specifically addresses "Deserialization of Untrusted Data" and represents a classic example of how insecure deserialization can lead to remote code execution. The attack vector requires an authenticated user context, meaning that the attacker must already have some level of access to the web application to initiate the session manipulation process, but once established, the impact can be devastating.
The operational impact of CVE-2016-0714 extends beyond simple privilege escalation, as successful exploitation can lead to complete system compromise and unauthorized access to sensitive data. Attackers can leverage this vulnerability to execute commands on the server, potentially gaining access to databases, file systems, and other applications running on the same infrastructure. The vulnerability affects organizations using Tomcat in production environments where session management is utilized, particularly web applications that store complex objects in user sessions. This includes enterprise applications, e-commerce platforms, and any system where user sessions contain serialized objects that could be manipulated by authenticated users. The risk is compounded by the fact that many organizations may not immediately patch their Tomcat installations, especially in environments where regular updates are not part of standard operational procedures. The vulnerability also intersects with ATT&CK technique T1059 which covers command and script injection, as the exploitation results in arbitrary code execution that can be used to establish persistent access or escalate privileges within the compromised environment.
Organizations should immediately implement mitigations by upgrading to patched versions of Apache Tomcat where the vulnerability has been addressed through proper session attribute validation and serialization controls. The recommended remediation involves upgrading to Tomcat versions 6.0.45, 7.0.68, 8.0.31, or 9.0.0.M2 respectively, which contain the necessary fixes to prevent unauthorized object deserialization. Additionally, administrators should implement strict session attribute validation policies, particularly for applications that store complex objects in sessions, and consider implementing session management restrictions such as disabling session persistence for applications that do not require it. Security monitoring should be enhanced to detect unusual session activity patterns and potential attempts to manipulate session data. Organizations should also review their application code to ensure that session attributes are properly sanitized and that no untrusted data is stored in session objects that could be exploited through deserialization attacks. The vulnerability demonstrates the importance of secure coding practices in session management and highlights the need for comprehensive security testing that includes serialization and deserialization scenarios as part of standard security assessments.