CVE-2021-34652 in Media Usage Plugin
Summary
by MITRE • 08/16/2021
The Media Usage WordPress plugin is vulnerable to Reflected Cross-Site Scripting via the id parameter in the ~/mmu_admin.php file which allows attackers to inject arbitrary web scripts, in versions up to and including 0.0.4.
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Analysis
by VulDB Data Team • 08/19/2021
The Media Usage WordPress plugin version 0.0.4 and earlier contains a critical reflected cross-site scripting vulnerability that exposes WordPress installations to potential exploitation. This vulnerability specifically affects the mmu_admin.php file where the id parameter is not properly sanitized or validated before being returned to users. The flaw represents a classic XSS vector that allows attackers to inject malicious scripts into web pages viewed by other users, creating a persistent threat vector within the WordPress ecosystem.
The technical implementation of this vulnerability stems from inadequate input validation and output encoding practices within the plugin's administrative interface. When the id parameter is processed through the mmu_admin.php file, it fails to undergo proper sanitization procedures that would normally prevent malicious payloads from being executed in the context of other users' browsers. This oversight creates a condition where attacker-controlled data flows directly into the web application's response without appropriate escaping or validation mechanisms. The vulnerability operates under CWE-79 which specifically addresses Cross-Site Scripting flaws in software applications.
The operational impact of this vulnerability extends beyond simple script injection, as it can enable attackers to perform various malicious activities including session hijacking, credential theft, and redirection to malicious sites. An attacker could craft a malicious URL containing a script payload that, when clicked by an authenticated administrator, would execute in the administrator's browser context. This scenario presents a significant risk since administrators typically possess elevated privileges and access to sensitive system functions. The vulnerability aligns with ATT&CK technique T1566.001 which covers Phishing with Malicious Attachments and links to broader attack chains involving credential compromise and privilege escalation.
Mitigation strategies should include immediate plugin updates to versions that address this vulnerability, as well as implementing proper input validation and output encoding measures. Organizations should also consider implementing Content Security Policy headers to limit script execution and monitor for suspicious parameter values in web server logs. Additionally, regular security audits of WordPress plugins and themes should be conducted to identify similar vulnerabilities. The vulnerability demonstrates the importance of proper security practices in plugin development and highlights the need for comprehensive input validation across all user-controllable parameters within web applications.