CVE-2023-5338 in Theme Blvd Shortcodes Plugin
Summary
by MITRE • 11/22/2023
The Theme Blvd Shortcodes plugin for WordPress is vulnerable to Stored Cross-Site Scripting via shortcodes in versions up to, and including, 1.6.8 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 Theme Blvd Shortcodes plugin for WordPress presents a critical stored cross-site scripting vulnerability that affects versions up to and including 1.6.8. This vulnerability stems from inadequate input sanitization and output escaping mechanisms within the plugin's shortcode handling functionality. The flaw allows authenticated attackers who possess contributor-level permissions or higher to inject malicious scripts into WordPress pages through shortcode attributes, creating a persistent threat that executes whenever any user accesses the compromised page.
The technical nature of this vulnerability aligns with CWE-79, which specifically addresses cross-site scripting flaws where insufficient sanitization of user-supplied data permits malicious scripts to be executed in the context of the victim's browser. The vulnerability operates through the plugin's shortcode processing system where user-provided attributes are not properly escaped before being rendered in HTML output. This creates an environment where attacker-controlled data can be injected directly into the page structure, enabling the execution of arbitrary JavaScript code within the victim's browser context.
From an operational perspective, this vulnerability represents a significant risk to WordPress installations that utilize the Theme Blvd Shortcodes plugin. The requirement for contributor-level permissions or higher means that the attack vector is not limited to unauthenticated threats but rather exploits compromised accounts or accounts with elevated privileges. The stored nature of the vulnerability means that once a malicious shortcode is injected, it persists in the database and affects all users who view the affected pages, potentially leading to widespread execution of malicious payloads across the site's user base.
The impact of this vulnerability extends beyond simple script execution as it can enable various malicious activities including session hijacking, data exfiltration, and redirection to malicious sites. Attackers can leverage this vulnerability to steal cookies, credentials, or other sensitive information from authenticated users who access compromised pages. The vulnerability also supports more sophisticated attacks such as defacement of content, injection of malicious advertisements, or establishment of command and control channels through the compromised WordPress installation.
Mitigation strategies for this vulnerability should focus on immediate remediation through plugin updates to versions that address the sanitization and escaping deficiencies. Organizations should implement strict input validation for all shortcode attributes and ensure proper output escaping before rendering user-supplied data in HTML contexts. Additionally, implementing principle of least privilege access controls can limit the damage scope by restricting contributor-level permissions to only trusted users. Regular security auditing of WordPress plugins and maintaining updated security practices aligns with ATT&CK technique T1548.003 for privilege escalation and defense in depth strategies. The vulnerability demonstrates the importance of proper input validation and output escaping as fundamental security controls that should be implemented across all web applications to prevent XSS attacks.