CVE-2018-0590 in Ultimate Member Plugin
Summary
by MITRE
Ultimate Member plugin prior to version 2.0.4 for WordPress allows remote authenticated attackers to bypass access restriction to modify the other users profiles via unspecified vectors.
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Analysis
by VulDB Data Team • 02/05/2020
The CVE-2018-0590 vulnerability affects the Ultimate Member WordPress plugin version 2.0.3 and earlier, representing a critical access control flaw that undermines the security posture of WordPress installations. This vulnerability specifically targets the plugin's user profile management functionality and allows authenticated attackers to escalate their privileges and modify other users' profiles without proper authorization. The flaw exists within the plugin's permission validation mechanisms, creating a path for malicious actors who have gained legitimate user credentials to exploit the system's trust model.
The technical implementation of this vulnerability stems from inadequate input validation and insufficient access control checks within the Ultimate Member plugin's profile modification endpoints. Attackers with valid user accounts can manipulate the system's permission model through unspecified vectors that likely involve parameter manipulation or direct API calls that bypass the intended user scope restrictions. This flaw operates at the application layer and leverages the trust relationship between authenticated users and the plugin's backend services, making it particularly dangerous as it requires minimal additional attack vectors beyond initial authentication.
The operational impact of CVE-2018-0590 extends far beyond simple profile modification capabilities, as it enables attackers to potentially access sensitive user data, modify user roles and permissions, and compromise the integrity of user accounts within the WordPress ecosystem. This vulnerability directly violates the principle of least privilege and can lead to cascading security issues including privilege escalation, data breaches, and potential account takeovers. The affected environment becomes vulnerable to insider threats and coordinated attacks where malicious users can exploit their legitimate access to compromise other users' accounts, making it particularly concerning for organizations with multiple users and sensitive data.
Organizations should implement immediate mitigation strategies including upgrading to Ultimate Member version 2.0.4 or later, which contains the necessary patches to address the access control bypass vulnerability. Security teams should also consider implementing network-level monitoring to detect unusual profile modification patterns and establish robust user access auditing procedures. The vulnerability aligns with CWE-285 which addresses improper access control issues, and maps to ATT&CK technique T1078 for valid accounts and privilege escalation. Additional defensive measures include restricting administrative privileges, implementing multi-factor authentication, and conducting regular security assessments of third-party plugins to identify similar vulnerabilities that could compromise the overall security architecture.
This vulnerability demonstrates the critical importance of proper access control implementation in web applications and highlights the risks associated with plugin-based security solutions. The flaw represents a classic example of how seemingly minor permission validation issues can create significant security risks in complex web environments where multiple authentication and authorization systems interact. Organizations should treat this vulnerability as a wake-up call to review their entire plugin ecosystem and implement comprehensive security monitoring to detect similar issues before they can be exploited by malicious actors.