Gravity Forms <= 2.9.30 - Unauthenticated Stored Cross-Site Scripting via Consent Field Hidden Input

The Gravity Forms plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Consent field hidden inputs in versions up to and including 2.9.30. This is due to a flawed state validation mechanism that fails open when input is sanitized by wp_kses(), combined with insufficient output escaping. The state validation logic creates two hashes (raw input and wp_kses-sanitized input) and only fails validation if BOTH hashes don't match the original state. When an attacker injects XSS payloads using tags stripped by wp_kses() (like <svg>), the sanitized hash matches while the malicious raw value is preserved and saved to the database. When administrators view the Entries List page, the stored malicious consent label is retrieved and output without escaping, causing the XSS payload to execute. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in entries that will execute whenever an authenticated administrator accesses the entries list page.

Requests carrying this pattern arrive without a session, so nothing upstream of the firewall gets a chance to reject them: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: Gravity Forms 2.9.31 closes this, and updating the plugin is the step that ends it.

• Firewall
• Login Security
• Alerts