CVE-2016-9284 in Exponent
Summary
by MITRE
getUsersByJSON in framework/modules/users/controllers/usersController.php in Exponent CMS v2.4.0 allows remote attackers to read user information via users/getUsersByJSON/sort/ and a trailing string.
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Analysis
by VulDB Data Team • 10/03/2022
The vulnerability identified as CVE-2016-9284 affects Exponent CMS version 2.4.0 and resides within the framework/modules/users/controllers/usersController.php file. This issue manifests through the getUsersByJSON endpoint which processes user information retrieval requests. The flaw occurs when attackers exploit a specific parameter handling mechanism that accepts a sort parameter followed by a trailing string, allowing unauthorized access to sensitive user data. The vulnerability represents a critical security flaw that undermines the application's access control mechanisms and user privacy protections. This type of vulnerability falls under CWE-200, which describes improper exposure of sensitive information, and specifically aligns with CWE-284, addressing improper access control mechanisms.
The technical implementation of this vulnerability stems from inadequate input validation and parameter sanitization within the usersController.php file. When the getUsersByJSON endpoint receives a request with a sort parameter followed by additional string data, the application fails to properly validate or sanitize the input before processing user data retrieval operations. This allows attackers to manipulate the parameter structure to bypass normal access controls and extract user information that should be restricted. The trailing string component in the URL path creates an opportunity for parameter injection attacks where malicious input can alter the intended functionality of the user retrieval mechanism. The vulnerability essentially enables a path traversal or parameter manipulation attack that can expose user credentials, personal information, and other sensitive data.
The operational impact of CVE-2016-9284 is severe and multifaceted for organizations running Exponent CMS v2.4.0. Attackers can systematically enumerate user accounts, potentially harvesting usernames, email addresses, and other identifying information that could be used for further attacks including credential stuffing, social engineering, or targeted phishing campaigns. The vulnerability also poses significant risk to user privacy and organizational security posture, as it allows unauthorized access to user databases without proper authentication. This type of information disclosure attack can lead to cascading security issues where compromised user data is used to gain deeper access to systems or networks. From an attacker's perspective, this vulnerability aligns with ATT&CK technique T1087.001 for account discovery and T1566.001 for credential harvesting, making it a valuable tool in the threat actor's arsenal.
Mitigation strategies for CVE-2016-9284 require immediate implementation of proper input validation and parameter sanitization controls within the affected Exponent CMS application. Organizations should implement strict validation of all user input parameters, particularly those used in data retrieval operations, to prevent parameter manipulation attacks. The most effective approach involves implementing proper access control checks before processing any user data requests and ensuring that sort parameters are properly sanitized and validated against a predefined whitelist of acceptable values. Additionally, organizations should consider implementing rate limiting and monitoring mechanisms to detect anomalous access patterns that might indicate exploitation attempts. The recommended solution includes upgrading to a patched version of Exponent CMS, as the vulnerability was addressed in subsequent releases. Security teams should also implement network segmentation and access controls to limit exposure of the affected application and establish comprehensive logging and monitoring to detect unauthorized access attempts. From a compliance perspective, this vulnerability directly impacts data protection requirements under standards such as gdpr and hipaa, making immediate remediation essential for regulatory compliance and risk management purposes.