CVE-2024-8964 in Image Optimizer, Resizer and CDN Plugin
Summary
by MITRE • 10/08/2024
The Image Optimizer, Resizer and CDN – Sirv plugin for WordPress is vulnerable to Stored Cross-Site Scripting via SVG File uploads in all versions up to, and including, 7.2.9 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with Author-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses the SVG file.
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Analysis
by VulDB Data Team • 12/05/2025
The Image Optimizer, Resizer and CDN – Sirv plugin for WordPress presents a critical security vulnerability classified as stored cross-site scripting through SVG file uploads. This vulnerability affects all plugin versions up to and including 7.2.9, creating a persistent threat vector that can be exploited by authenticated attackers holding at least Author-level privileges within the WordPress environment. The flaw stems from inadequate input sanitization mechanisms and insufficient output escaping protocols that fail to properly validate and sanitize SVG file content before storage and subsequent execution.
The technical implementation of this vulnerability occurs when an attacker uploads a malicious SVG file that contains embedded JavaScript code or other malicious payloads. The plugin's insufficient input validation allows these potentially harmful files to be stored within the WordPress media library without proper sanitization. When legitimate users access pages containing these compromised SVG files, the stored malicious scripts execute within their browser context, creating a persistent cross-site scripting attack vector. This represents a direct violation of the principle of least privilege and demonstrates a fundamental flaw in the plugin's security architecture.
From an operational impact perspective, this vulnerability enables attackers to execute arbitrary code within the context of authenticated user sessions, potentially leading to complete account compromise, data exfiltration, and privilege escalation within the WordPress environment. The stored nature of this XSS vulnerability means that the malicious payload remains active until manually removed from the system, creating a long-term security risk that can affect multiple users over extended periods. Attackers can leverage this vulnerability to steal session cookies, redirect users to malicious sites, or perform actions on behalf of authenticated users.
The vulnerability aligns with CWE-79, which specifically addresses cross-site scripting flaws, and represents a classic case of insufficient output escaping in web applications. From an attack framework perspective, this vulnerability maps to ATT&CK technique T1566.002, which covers social engineering through malicious file attachments, and T1059.007, covering scripting through web shells or malicious code execution. Organizations should immediately implement mitigations including plugin version updates to the latest secure release, implementing additional input validation measures, and monitoring for unauthorized SVG file uploads. Additionally, administrators should consider implementing web application firewalls and restricting file upload capabilities to minimize the attack surface while maintaining operational functionality.
The remediation approach requires immediate patching of the Sirv plugin to version 7.2.10 or later, which contains the necessary input sanitization and output escaping fixes. Security teams should also implement comprehensive monitoring of file upload activities, particularly for SVG files, and establish automated scanning processes to detect potentially malicious content. Regular security audits of WordPress plugins and themes should be conducted to identify similar vulnerabilities, while user access controls should be strictly enforced to limit upload privileges to only essential administrative personnel. This vulnerability underscores the critical importance of maintaining up-to-date security practices and the necessity of implementing defense-in-depth strategies to protect WordPress environments from persistent threats.