Mavo DOM Clobbering Vulnerability Allowing Arbitrary Code Execution

A DOM clobbering vulnerability has been identified in Mavo version 0.3.2. This vulnerability allows attackers to execute arbitrary code by injecting crafted HTML elements. The issue arises because Mavo's plugin-loading mechanism can be manipulated to load dependencies from an attacker's controlled domain, potentially leading to cross-site scripting (XSS) attacks.

Impact

Exploitation of this vulnerability could lead to arbitrary code execution, with the injected code being executed in the context of the affected web page. This could allow for cross-site scripting (XSS) attacks, where an attacker could execute malicious scripts in the user's browser.

Reproduction

To reproduce this vulnerability, inject an HTML element such as an image tag with an unsanitized name attribute into a web page that uses Mavo 0.3.2. This can be done through a post or comment. The injected element will shadow the 'currentScript' reference, allowing the execution of arbitrary code by manipulating Mavo's plugin-loading mechanism.

Remediation

To address this vulnerability, Mavo's plugin-loading code should be updated to include a type check that ensures 'document.currentScript' only references '<script>' elements. This will prevent the injection of attacker-controlled HTML elements from being exploited.