CVE-2024-53387: Umeditor RCE Vulnerability

CVE-2024-53387 Overview

CVE-2024-53387 is a Document Object Model (DOM) Clobbering vulnerability in umeditor version 1.2.3, a browser-based WYSIWYG HTML editor. Attackers can execute arbitrary code by supplying a crafted HTML element that overrides JavaScript variables or functions referenced by the editor. The flaw is categorized under [CWE-79] (Cross-Site Scripting) and requires user interaction to trigger. Successful exploitation results in arbitrary script execution in the victim's browser context, compromising confidentiality, integrity, and availability of the affected application session.

Critical Impact
Attackers can achieve arbitrary code execution in a victim's browser by injecting a crafted HTML element processed by the vulnerable editor, leading to full session compromise.

Affected Products

umeditor 1.2.3
Applications embedding the vulnerable umeditor build
Web platforms relying on umeditor for HTML content editing

Discovery Timeline

2025-03-03 - CVE-2024-53387 published to NVD
2025-07-07 - Last updated in NVD database

Technical Details for CVE-2024-53387

Vulnerability Analysis

The vulnerability resides in how umeditor processes user-supplied HTML markup before rendering or sanitizing content. DOM Clobbering abuses the browser behavior where named HTML elements (using id or name attributes) are exposed as named properties on the document object and on parent DOM nodes. When client-side JavaScript references global variables or object properties without verifying their type, an attacker-supplied element can shadow those identifiers with DOM node references. The editor's internal logic then operates on the attacker-controlled element instead of the intended value, enabling script execution paths that bypass normal sanitization. Because the attack requires only a single crafted HTML element, payloads can be embedded in shared documents, comments, or forum posts processed by the editor.

Root Cause

The root cause is unsafe reliance on global property lookups within umeditor's client-side code without verifying that resolved values are of the expected type. HTML sanitization in umeditor v1.2.3 fails to strip or rename id and name attributes that collide with sensitive JavaScript identifiers, allowing injected nodes to clobber script-defined variables.

Attack Vector

Exploitation is performed over the network and requires user interaction, such as loading a page that renders attacker-controlled HTML through the editor. An attacker submits a payload containing an HTML element whose id or name matches a variable the editor reads at runtime. When the page evaluates the clobbered reference, the attacker gains a foothold for arbitrary JavaScript execution within the application's origin.

A proof-of-concept payload demonstrating the DOM Clobbering primitive is published in the GitHub Gist PoC Implementation. The PoC illustrates how a crafted element can hijack a property lookup used by the editor to load configuration or callback functions.

Detection Methods for CVE-2024-53387

Indicators of Compromise

HTML content submitted to umeditor instances containing <form>, <img>, <iframe>, or <a> elements with id or name attributes matching sensitive JavaScript identifiers
Unexpected outbound requests from browsers loading editor pages, indicating injected script execution
Editor-rendered pages emitting console errors related to undefined methods on what should be plain objects

Detection Strategies

Inspect stored editor content for HTML elements whose attributes target known umeditor global identifiers
Deploy Content Security Policy (CSP) reporting endpoints to capture script-src violations originating from editor-rendered pages
Review web application logs for POST requests containing suspicious id/name attribute combinations submitted through editor endpoints

Monitoring Recommendations

Monitor browser telemetry and Real User Monitoring (RUM) data for unexpected JavaScript exceptions on pages embedding umeditor
Alert on inline script execution or external script loads from pages that render user-submitted editor content
Track version banners and asset hashes for umeditor 1.2.3 across production deployments

How to Mitigate CVE-2024-53387

Immediate Actions Required

Inventory all applications using umeditor 1.2.3 and identify exposed editor endpoints
Apply server-side HTML sanitization that strips or rewrites id and name attributes from user-submitted markup before storage or rendering
Enforce a strict Content Security Policy that disallows unsafe-inline and restricts script sources for any page embedding the editor

Patch Information

No vendor patch is referenced in the NVD entry for umeditor 1.2.3. The project has not published a fixed release for CVE-2024-53387. Consult the GitHub Gist PoC Implementation for technical context on the clobbering primitive and required defensive changes.

Workarounds

Replace umeditor with a maintained editor that performs DOM Clobbering-aware sanitization, such as libraries built on DOMPurify with SANITIZE_DOM enabled
Filter inbound HTML through an allowlist that removes id, name, and form attributes from untrusted elements
Isolate editor rendering inside a sandboxed iframe with the sandbox attribute set to restrict script execution and same-origin access

bash

# Example NGINX response header enforcing a restrictive CSP for pages rendering editor output
add_header Content-Security-Policy "default-src 'self'; script-src 'self'; object-src 'none'; base-uri 'none'; frame-ancestors 'self'";