CVE-2024-53388: Mavo DOM Clobbering RCE Vulnerability

CVE-2024-53388 Overview

CVE-2024-53388 is a Document Object Model (DOM) Clobbering vulnerability in mavo v0.3.2, a JavaScript library for creating interactive web applications without code. Attackers can execute arbitrary code by supplying a crafted HTML element that manipulates DOM properties referenced by the library. The flaw is classified under [CWE-79] (Improper Neutralization of Input During Web Page Generation). Exploitation requires user interaction, typically when a victim loads an attacker-controlled page or third-party content embedded in a Mavo-powered site.

Critical Impact

Successful exploitation allows arbitrary JavaScript execution in the victim's browser context, leading to session hijacking, data theft, and full compromise of the affected web application.

Affected Products

• Mavo mavo version 0.3.2
• Web applications embedding Mavo v0.3.2 client-side library
• Static sites and dashboards relying on Mavo for data binding

Discovery Timeline

• 2025-03-03 - CVE-2024-53388 published to the National Vulnerability Database (NVD)
• 2025-07-07 - Last updated in NVD database

Technical Details for CVE-2024-53388

Vulnerability Analysis

The vulnerability arises from how Mavo references global properties without validating their type or origin. DOM Clobbering attacks abuse the browser behavior of exposing named HTML elements as JavaScript properties on the window and document objects. When attacker-controlled HTML reaches the page, elements with specific id or name attributes can shadow expected JavaScript variables. Mavo then consumes these clobbered references as trusted values, leading to script execution paths controlled by the attacker.

This weakness is a client-side injection issue that requires the victim to load a page containing the crafted markup. Sites that allow user-supplied HTML, such as content management systems, comment sections, or markdown previewers, are particularly exposed when Mavo is also loaded on the same origin.

Root Cause

The root cause is unsafe lookup of global objects and named elements within the Mavo library. The library trusts properties accessible through the global scope without verifying that they originate from authorized script execution rather than HTML element clobbering. Refer to the GitHub Gist Vulnerability Report for the proof-of-concept analysis.

Attack Vector

An attacker injects HTML containing elements with crafted id or name attributes into a page that loads Mavo v0.3.2. When Mavo executes, it dereferences a global identifier expected to hold a script-defined value but instead receives an HTMLElement reference under attacker control. The attacker chains this primitive to reach a script source or evaluation sink, achieving arbitrary code execution in the victim's browser. No authentication is required, and exploitation occurs over the network through a single page load.

No verified exploitation code is publicly available. See the GitHub Gist Vulnerability Report for the original technical write-up.

Detection Methods for CVE-2024-53388

Indicators of Compromise

• HTML elements with suspicious id or name attributes such as config, script, default, or names matching internal Mavo identifiers
• Inline <a>, <img>, <form>, or <iframe> tags containing href or src values pointing to attacker-controlled domains
• Unexpected outbound requests from browsers to unknown JavaScript hosts immediately after rendering Mavo-enabled pages

Detection Strategies

• Audit web application logs for HTML form submissions or user content containing tags with reserved attribute names used by Mavo
• Deploy Content Security Policy (CSP) reports to capture violations triggered by clobbered script loads
• Inspect saved user-generated content in databases for HTML attributes mimicking JavaScript global names

Monitoring Recommendations

• Monitor browser console errors and CSP reports for unexpected script-src violations on pages that include Mavo
• Track network telemetry for client requests to untrusted origins originating from pages embedding Mavo
• Alert on modifications to static assets and HTML templates that reference mavo.js version 0.3.2

How to Mitigate CVE-2024-53388

Immediate Actions Required

• Inventory all sites and applications that load Mavo v0.3.2 and remove the library where it is not essential
• Sanitize all user-supplied HTML using an allowlist-based parser such as DOMPurify before rendering
• Enforce a strict Content Security Policy that disables inline scripts and restricts script-src to trusted origins

Patch Information

No official patched release addressing CVE-2024-53388 is referenced in the NVD entry at the time of publication. Consult the upstream Mavo project and the GitHub Gist Vulnerability Report for the latest remediation guidance.

Workarounds

• Strip or escape HTML attributes id and name from any user-controlled markup before storage or rendering
• Isolate Mavo-rendered content inside a sandboxed <iframe> with a separate origin to limit DOM Clobbering reach
• Replace Mavo v0.3.2 with a maintained alternative for data-binding features in production deployments

# Example Content Security Policy header to mitigate DOM Clobbering script execution
Content-Security-Policy: default-src 'self'; script-src 'self'; object-src 'none'; base-uri 'none'; require-trusted-types-for 'script'