CVE-2017-18537 in visitors-online Plugin
Summary
by MITRE
The visitors-online plugin before 1.0.0 for WordPress has multiple XSS issues.
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Analysis
by VulDB Data Team • 11/28/2023
The vulnerability identified as CVE-2017-18537 affects the visitors-online plugin for WordPress, specifically versions prior to 1.0.0, and represents a critical cross-site scripting vulnerability that exposes WordPress installations to significant security risks. This issue stems from inadequate input validation and output sanitization within the plugin's codebase, allowing attackers to inject malicious scripts into web pages viewed by other users. The vulnerability manifests in multiple locations within the plugin's functionality where user-supplied data is directly incorporated into HTML output without proper escaping or encoding mechanisms. Such flaws create persistent attack vectors that can be exploited by malicious actors to compromise user sessions, steal sensitive information, or manipulate the plugin's behavior to serve malicious content.
The technical implementation of this vulnerability aligns with CWE-79, which categorizes cross-site scripting flaws as weaknesses in input validation and output encoding. The plugin fails to properly sanitize data received from visitors or administrators, creating opportunities for attackers to inject script tags, javascript payloads, or other malicious code that executes in the context of other users' browsers. These XSS vulnerabilities typically occur when the plugin stores or displays user-provided data without appropriate HTML entity encoding or script sanitization, allowing attackers to craft malicious inputs that persist in the plugin's database or display areas. The vulnerability's impact extends beyond simple script execution as it can be leveraged to perform session hijacking, deface websites, or redirect users to malicious domains.
The operational impact of CVE-2017-18537 is severe for WordPress site administrators and end users who rely on the visitors-online plugin for tracking website traffic or user engagement metrics. Attackers can exploit these vulnerabilities to execute arbitrary code within users' browsers, potentially leading to complete compromise of user sessions through cookie theft or session manipulation. The vulnerability affects not only the plugin's core functionality but also the broader WordPress ecosystem, as compromised visitors-online displays can be used to distribute malware or phishing content to other website visitors. This type of vulnerability is particularly dangerous in environments where the plugin is used to display sensitive visitor data or where administrators have elevated privileges that could be exploited through session manipulation.
Mitigation strategies for CVE-2017-18537 require immediate action to upgrade to the patched version 1.0.0 or later, as this represents the primary and most effective remediation approach. Organizations should also implement comprehensive input validation and output encoding measures across all plugin components, ensuring that any data entered by users is properly sanitized before storage or display. Security practitioners should consider implementing content security policies to limit the execution of inline scripts and restrict external resource loading. Additionally, monitoring for suspicious activity in the plugin's data storage areas and regular security audits of third-party WordPress plugins should be established as standard practices. The vulnerability's classification under ATT&CK technique T1548.001 highlights the importance of maintaining secure plugin ecosystems and the potential for these vulnerabilities to be leveraged as persistence mechanisms within compromised WordPress installations.