Files
genai-toolbox/internal/server/static
Mohammed Tanveer d1358916d8 chore(ui): prevent script execution in Toolbox UI rendering (#2331)
# Defensive Security Hardening: Prevent Script Execution in Toolbox UI
Rendering

> **Note:** This issue was identified during security research and
reviewed previously.
> While typical deployments operate within a trusted configuration
model, addressing this behavior was recommended as a defense-in-depth
improvement. This PR describes the implemented fix.

## Overview

This change improves the safety of the GenAI Toolbox UI by preventing
unintended JavaScript execution when rendering values derived from tool
configuration files.

Previously, certain fields from tool definitions were rendered directly
into HTML contexts without escaping. As a result, tool definitions
containing embedded HTML or script payloads could trigger JavaScript
execution when viewed in the dashboard. While this occurs within the
same trust boundary as the configuration owner, escaping these values by
default avoids unexpected execution and improves robustness.

## Changes Implemented

### 1. New Utility
- Added `sanitize.js` which exports a strict `escapeHtml()` function.
- Escapes dangerous characters: `&`, `<`, `>`, `"`, `'`, `/`, `` ` ``.
- Performs strict type checking, rendering `null` and `undefined` values
as empty strings.

### 2. Input Handling
- Updated `internal/server/static/js/toolDisplay.js` to wrap `tool.name`
and `tool.description` with `escapeHtml()` prior to rendering them into
the DOM.

### 3. Error Handling
- Updated `internal/server/static/js/loadTools.js` to sanitize error
messages that may reflect user-controlled or derived input before
rendering.

## Validation

- Verified behavior using tool definition files containing common script
execution vectors.
- Confirmed that embedded HTML and script payloads are rendered as
literal text.
- Verified that standard and existing tool definitions continue to
render correctly without functional regression.

## Notes

This change is a defense-in-depth hardening measure.  
It does not modify the existing trust model or intended usage patterns,
but ensures safer default rendering behavior and avoids unintended
script execution in the UI.

## Attribution

**Contributor:** Mohammed Tanveer (threatpointer)

---------

Co-authored-by: threatpointer <mohammed.tanveer1@gmail.com>
Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>
Co-authored-by: Yuan Teoh <45984206+Yuan325@users.noreply.github.com>
2026-01-29 00:22:24 +00:00
..