CVE-2025-30625: AppBanners WordPress Plugin XSS Vulnerability

CVE-2025-30625 Overview

CVE-2025-30625 is a stored Cross-Site Scripting (XSS) vulnerability in the Matt Pramschufer AppBanners WordPress plugin. The flaw affects all plugin versions up to and including 1.5.14 and is tracked under [CWE-79]: Improper Neutralization of Input During Web Page Generation. An authenticated attacker with high privileges can inject persistent JavaScript payloads that execute in the browsers of users who view the affected pages. Because the attack scope changes to affected resources beyond the vulnerable component, exploitation can influence other browser contexts on the WordPress site.

Critical Impact

An authenticated attacker can store malicious scripts in AppBanners content that execute in visitors' browsers, enabling session theft, administrative action hijacking, and content manipulation.

Affected Products

• Matt Pramschufer AppBanners WordPress plugin versions up to and including 1.5.14
• WordPress sites with the AppBanners plugin installed and activated
• Any browser session rendering unsanitized AppBanners output

Discovery Timeline

• 2025-06-06 - CVE-2025-30625 published to the National Vulnerability Database
• 2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-30625

Vulnerability Analysis

The vulnerability stems from insufficient input neutralization in the AppBanners plugin. User-supplied data submitted through plugin-managed fields is stored in the WordPress database and later rendered into HTML output without proper escaping or contextual encoding. This allows an attacker to persist arbitrary JavaScript that executes each time a victim loads a page containing the injected banner content.

Exploitation requires an authenticated session with elevated privileges and some form of user interaction to trigger the payload. Despite these constraints, the stored nature of the flaw means a single injection can affect many subsequent visitors, including administrators. The changed scope indicates that script execution can impact resources managed by a different security authority than the vulnerable plugin.

Root Cause

The root cause is missing or inadequate output encoding when AppBanners renders stored banner data into WordPress pages. Standard WordPress sanitization helpers such as esc_html(), esc_attr(), or wp_kses() are not applied consistently to attacker-controlled input before it reaches the browser. As a result, HTML and JavaScript tokens are interpreted rather than displayed as literal text.

Attack Vector

An authenticated attacker with high-privilege access to the plugin's administrative interface submits a payload containing HTML or JavaScript into a banner field. The malicious content is written to the database as part of the banner configuration. When a legitimate user, including administrators, loads a page that renders the banner, the injected script runs in the context of the WordPress origin. The attacker can then exfiltrate session cookies, perform actions on behalf of the victim, or pivot to further compromise. Refer to the Patchstack WordPress Vulnerability Analysis for advisory details.

Detection Methods for CVE-2025-30625

Indicators of Compromise

• AppBanners database entries containing <script>, onerror=, onload=, or javascript: tokens in banner content fields
• Unexpected outbound HTTP requests from browser sessions loading pages that render AppBanners output
• Administrative user accounts performing actions immediately after loading an AppBanners-enabled page
• WordPress audit log entries showing banner modifications by unusual accounts or from unusual IP addresses

Detection Strategies

• Query the WordPress wp_options and wp_postmeta tables for AppBanners records containing HTML event handlers or script tags
• Deploy a web application firewall rule that flags POST requests to AppBanners administrative endpoints containing script payloads
• Correlate authenticated admin sessions with subsequent browser-side script execution anomalies through endpoint telemetry

Monitoring Recommendations

• Monitor changes to WordPress plugin configuration data, especially fields owned by AppBanners
• Alert on WordPress administrator logins from new geographies followed by banner edits
• Track Content Security Policy (CSP) violation reports for inline script execution on pages containing banners

How to Mitigate CVE-2025-30625

Immediate Actions Required

• Audit installed WordPress plugins and identify sites running AppBanners 1.5.14 or earlier
• Deactivate the AppBanners plugin until a patched release is confirmed available and installed
• Review all existing banner entries for HTML or JavaScript content and remove suspicious payloads
• Rotate credentials for any WordPress administrator accounts that may have loaded affected pages

Patch Information

At the time of publication, the vendor advisory published by Patchstack identifies all versions through 1.5.14 as affected. Administrators should upgrade to any subsequently released version that documents a fix for CVE-2025-30625 and validate the fix in a staging environment before production rollout.

Workarounds

• Restrict administrative access to the AppBanners plugin to a minimal set of trusted users
• Enforce a strict Content Security Policy that disallows inline scripts on pages rendering banners
• Place the WordPress admin interface behind IP allowlisting or a VPN to reduce the attacker population
• Enable multi-factor authentication on all WordPress administrator accounts to raise the cost of privileged access abuse

# Example Content Security Policy header to block inline script execution
Header set Content-Security-Policy "default-src 'self'; script-src 'self'; object-src 'none'; base-uri 'self'; frame-ancestors 'self'"