CVE-2023-5667 in Tab Ultimate Plugin
Summary
by MITRE • 11/22/2023
The Tab Ultimate plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's shortcodes in all versions up to, and including, 1.3 due to insufficient input sanitization and output escaping on user supplied attributes. This makes it possible for authenticated attackers with contributor-level and above permissions to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.
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Analysis
by VulDB Data Team • 04/11/2026
The Tab Ultimate plugin for WordPress represents a significant security vulnerability classified as CVE-2023-5667, affecting all versions up to and including 1.3. This vulnerability manifests as a stored cross-site scripting flaw that exploits the plugin's shortcode implementation, creating a persistent threat vector within WordPress environments. The flaw specifically arises from inadequate input sanitization and output escaping mechanisms that fail to properly validate user-supplied attributes within the plugin's shortcode processing functionality.
The technical nature of this vulnerability stems from the plugin's failure to adequately sanitize and escape user input before storing and subsequently rendering it within web pages. When authenticated attackers with contributor-level permissions or higher utilize the plugin's shortcode features, they can inject malicious JavaScript code through attributes that are not properly validated or escaped. This stored payload persists in the database and executes whenever any user accesses a page containing the injected content, creating a persistent threat that can affect multiple users without requiring repeated exploitation attempts.
The operational impact of this vulnerability extends beyond simple script execution, as it provides attackers with a persistent foothold within the WordPress environment. Contributors and above have sufficient privileges to create and modify content, making this attack vector particularly dangerous as it can be leveraged to establish backdoors, steal session cookies, perform unauthorized actions, or redirect users to malicious sites. The stored nature of the XSS means that the attack remains active until the malicious content is manually removed from the database or the plugin is updated, potentially affecting all users who access pages containing the compromised shortcodes.
This vulnerability aligns with CWE-79 which specifically addresses cross-site scripting flaws in web applications, and demonstrates characteristics consistent with ATT&CK technique T1566.001 related to spearphishing attachments. The exploitation requires minimal privileges and can result in significant compromise of user sessions and data integrity. Organizations should prioritize immediate remediation through plugin updates, implement proper input validation at multiple layers, and consider implementing web application firewalls to detect and prevent such attacks. Additionally, regular security audits of WordPress plugins and enforcement of least privilege principles can help mitigate the risk of similar vulnerabilities in the broader WordPress ecosystem.
The persistence of this vulnerability across multiple versions highlights the importance of regular security updates and the need for developers to implement comprehensive input sanitization and output escaping mechanisms. Security professionals should monitor plugin repositories for similar vulnerabilities and ensure that all WordPress installations maintain current security patches to prevent exploitation of known weaknesses in third-party components.