MaxKB Eval Injection Vulnerability in Echarts Rendering Component Leading to Stored Cross-Site Scripting

An Eval Injection vulnerability has been identified in MaxKB, an open-source AI assistant for enterprise, specifically in versions through 2.7.1. This vulnerability resides in the Markdown rendering engine, allowing users interacting with the AI chat interface to execute arbitrary JavaScript in the browsers of other users, including administrators. The issue arises in the 'EchartsRander' component, which renders Apache Echarts graphs within Markdown responses. The vulnerability allows for Stored Cross-Site Scripting (XSS) exploitation.

Impact

Exploitation of this vulnerability allows for Stored Cross-Site Scripting (XSS) attacks, where injected JavaScript is executed in the context of the victim's browser.

Reproduction

To reproduce this vulnerability, create a Markdown response that includes an '<echarts_rander>' tag. Within the JSON content of this tag, include a 'option' field that contains JavaScript code to be executed. When the Markdown is rendered, the 'EchartsRander' component will evaluate the JavaScript using the 'eval()' function, executing the injected code in the browser of the user viewing the response.

Remediation

Users can upgrade to MaxKB version 2.8.0, where this vulnerability has been fixed.