CVE-2016-8900 in Exponent
Summary
by MITRE
Exponent CMS version 2.3.9 suffers from a Object Injection vulnerability in framework/modules/core/controllers/expTagController.php related to change_tags.
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Analysis
by VulDB Data Team • 09/24/2023
The vulnerability identified as CVE-2016-8900 affects Exponent CMS version 2.3.9 and represents a critical object injection flaw within the framework's core controllers. This vulnerability resides in the expTagController.php file and specifically relates to the change_tags functionality, creating a significant security risk for affected systems. The issue stems from insufficient input validation and sanitization mechanisms that fail to properly handle user-supplied data before processing it within the application's object-oriented architecture.
The technical flaw manifests when the application processes tag-related data through the change_tags function without adequate sanitization of input parameters. Attackers can exploit this weakness by injecting malicious serialized objects or data structures that get unserialized within the application context. This type of vulnerability falls under the CWE-502 category, which specifically addresses deserialization of untrusted data, making it particularly dangerous as it can lead to remote code execution or arbitrary code injection within the target environment. The vulnerability exploits the trust placed in application data processing, allowing attackers to manipulate the object instantiation flow and potentially execute malicious code with the privileges of the web application.
The operational impact of this vulnerability extends beyond simple data corruption or unauthorized access. When successfully exploited, the object injection flaw can enable attackers to execute arbitrary commands on the affected server, potentially leading to complete system compromise. This risk is exacerbated by the fact that the vulnerability exists within core application functionality that handles user-generated content, making it accessible through normal application usage patterns. The attack surface is particularly concerning given that Exponent CMS is a content management system where users regularly interact with tag-based features, providing multiple entry points for exploitation. Organizations running affected versions face potential data breaches, system takeovers, and unauthorized access to sensitive information stored within the CMS environment.
Mitigation strategies for CVE-2016-8900 require immediate action to address the root cause through proper input validation and sanitization mechanisms. System administrators should prioritize upgrading to the latest stable version of Exponent CMS where this vulnerability has been patched and remediated. The fix typically involves implementing proper data sanitization routines that prevent malicious serialized objects from being processed within the application's core functions. Additionally, implementing web application firewalls and input validation layers can provide additional defense-in-depth measures. Organizations should also conduct comprehensive security assessments of their CMS environments to identify similar vulnerabilities in other components and ensure that all third-party libraries and modules are updated to their latest secure versions. The vulnerability demonstrates the critical importance of secure coding practices and proper input validation in preventing object injection attacks, aligning with ATT&CK techniques focused on code injection and privilege escalation within web applications.