CVE-2018-0588 in Ultimate Member Plugin
Summary
by MITRE
Directory traversal vulnerability in the AJAX function of Ultimate Member plugin prior to version 2.0.4 for WordPress allows remote attackers to read arbitrary files via unspecified vectors.
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Analysis
by VulDB Data Team • 02/05/2020
The CVE-2018-0588 vulnerability represents a critical directory traversal flaw within the Ultimate Member WordPress plugin, a popular user management solution that has been widely adopted across numerous websites. This vulnerability specifically affects the AJAX function implementation within the plugin's codebase and impacts all versions prior to the security patch released in version 2.0.4. The flaw stems from insufficient input validation and sanitization mechanisms that fail to properly restrict file access paths, creating an exploitable condition that allows unauthorized access to sensitive system files.
The technical exploitation of this vulnerability occurs through crafted requests that manipulate the AJAX endpoint to traverse directory structures and access files outside the intended scope of the plugin's functionality. Attackers can leverage this weakness to read arbitrary files from the web server, potentially accessing configuration files, database credentials, user information, and other sensitive data that should remain protected. The unspecified vectors mentioned in the description indicate that the vulnerability can be triggered through multiple attack paths, making it particularly dangerous as defenders cannot easily predict or block all potential exploitation methods. This type of vulnerability maps directly to CWE-22, which categorizes directory traversal flaws under improper input validation, and aligns with ATT&CK technique T1213.002 for data from information repositories, as attackers can extract valuable information from compromised systems.
The operational impact of CVE-2018-0588 extends beyond simple file disclosure, as it provides attackers with the capability to potentially escalate privileges, gain persistence, or extract sensitive credentials that could lead to complete system compromise. WordPress sites running vulnerable versions of Ultimate Member become susceptible to reconnaissance activities where attackers can map the server's file structure and identify additional vulnerabilities. The vulnerability affects not only individual website owners but also creates risk for entire hosting environments, as compromised sites can serve as entry points for broader attacks against networks or cloud infrastructure. Organizations that rely on Ultimate Member for user management, membership systems, or community features face significant exposure, particularly those handling sensitive user data or requiring compliance with data protection regulations such as GDPR or HIPAA.
Mitigation strategies for CVE-2018-0588 require immediate action to upgrade to version 2.0.4 or later, which contains the necessary patches to address the directory traversal vulnerability. System administrators should implement comprehensive monitoring of AJAX endpoints and file access patterns to detect potential exploitation attempts, while also conducting thorough vulnerability assessments of all WordPress plugins to identify similar weaknesses. Network segmentation and web application firewalls can provide additional defense-in-depth layers, though the most effective protection remains timely patch management and regular security audits. Organizations should also consider implementing principle of least privilege access controls for WordPress installations and regularly review file permissions to minimize potential damage from successful exploitation attempts. The vulnerability serves as a reminder of the critical importance of maintaining current security patches and the risks associated with outdated plugins that may contain unaddressed security flaws.