CVE-2025-28870 Overview
CVE-2025-28870 is a DOM-Based Cross-Site Scripting (XSS) vulnerability [CWE-79] in the amoCRM WebForm plugin for WordPress. The flaw affects all versions up to and including 1.1. The plugin fails to properly neutralize user-supplied input during web page generation, allowing attackers to inject and execute arbitrary JavaScript in the victim's browser. Exploitation requires low-privileged authentication and user interaction, but the scope change means injected scripts can affect resources beyond the vulnerable component. Patchstack cataloged the issue and published an advisory covering affected releases.
Critical Impact
Authenticated attackers can execute arbitrary JavaScript in a victim's browser session, enabling session token theft, credential harvesting, and unauthorized actions performed on behalf of the targeted user.
Affected Products
- amoCRM WebForm plugin for WordPress (amocrm-webform)
- All versions up to and including 1.1
- WordPress sites with the plugin installed and active
Discovery Timeline
- 2025-03-11 - CVE-2025-28870 published to the National Vulnerability Database (NVD)
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-28870
Vulnerability Analysis
The vulnerability is a DOM-Based Cross-Site Scripting flaw in the amoCRM WebForm plugin. DOM-Based XSS occurs entirely within the client-side execution context, where JavaScript reads attacker-controlled input from a source such as document.location, document.URL, or window.name and writes it to a sink like innerHTML or document.write without proper encoding.
An attacker crafts a malicious URL or payload that, when processed by the plugin's client-side code, results in JavaScript execution in the victim's browser. Because the scope is changed, injected scripts may access resources belonging to other components rendered on the same page. The attack requires user interaction, typically by convincing a target to click a crafted link.
Root Cause
The root cause is improper neutralization of input during web page generation [CWE-79]. The plugin's client-side JavaScript passes untrusted values into a DOM sink without applying context-appropriate output encoding or sanitization. Any input reflected into HTML, attribute, or script contexts is executed as code rather than rendered as data.
Attack Vector
Exploitation is network-based and requires an authenticated user with low privileges to trigger the vulnerable code path. The attacker delivers a crafted request or link containing a JavaScript payload. When the victim's browser processes the plugin's DOM manipulation logic, the payload executes in the origin of the WordPress site. Successful exploitation can lead to session hijacking, forced administrative actions, and pivoting to further attacks against the WordPress installation.
No verified proof-of-concept code is publicly available. The vulnerability mechanism is described in prose based on the Patchstack Vulnerability Report.
Detection Methods for CVE-2025-28870
Indicators of Compromise
- Unusual query strings or URL fragments containing <script>, javascript:, onerror=, or encoded variants sent to pages hosting the amoCRM WebForm plugin.
- WordPress access logs showing repeated requests to plugin-related endpoints with anomalous parameter values.
- Unexpected outbound requests from authenticated user browsers to attacker-controlled domains shortly after visiting plugin-rendered pages.
Detection Strategies
- Inventory WordPress installations for the amocrm-webform plugin and confirm versions at or below 1.1.
- Deploy a Web Application Firewall (WAF) rule set to flag reflected script payloads targeting plugin parameters.
- Review browser console errors and Content Security Policy (CSP) violation reports for evidence of injected inline scripts.
Monitoring Recommendations
- Enable HTTP request logging on the reverse proxy or WAF and forward logs to a centralized analytics platform for pattern analysis.
- Monitor authenticated WordPress sessions for anomalous administrative actions immediately following link clicks or form submissions.
- Track plugin file integrity to detect unauthorized modifications following suspected exploitation.
How to Mitigate CVE-2025-28870
Immediate Actions Required
- Identify every WordPress site running the amoCRM WebForm plugin at version 1.1 or earlier and prioritize remediation.
- Deactivate the plugin if it is not essential to business operations until a vendor-supplied patch is validated and deployed.
- Rotate credentials and invalidate active sessions for any accounts that may have interacted with malicious links targeting affected pages.
Patch Information
At the time of publication, the Patchstack Vulnerability Report identifies all versions up to and including 1.1 as vulnerable. Administrators should monitor the plugin's WordPress.org listing and vendor channels for a fixed release and apply it as soon as it is available.
Workarounds
- Remove or deactivate the amoCRM WebForm plugin until an official patch is published.
- Deploy a strict Content Security Policy (CSP) that disallows inline script execution and restricts script sources to trusted origins.
- Configure WAF rules to block requests containing common XSS payload patterns directed at plugin endpoints.
# Example Content Security Policy header for Apache to reduce XSS impact
Header set Content-Security-Policy "default-src 'self'; script-src 'self'; object-src 'none'; base-uri 'self'; frame-ancestors 'self'"
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
