Summary

Vulnerability: Stored DOM XSS via Page Management Fields (Persistent Payload Injection)

• Stored Cross-Site Scripting via Unsanitized Page Creation and Editing Inputs

Description

The application fails to properly sanitize user-controlled input within the Page Management functionality when creating or editing pages. Multiple input fields accept attacker-controlled JavaScript payloads that are stored server-side.

These stored values are later rendered without proper output encoding across administrative page lists and public-facing page views, leading to stored DOM-based cross-site scripting (XSS).

Affected Functionality

• Page creation functionality
• Page editing functionality
• Page list and management views
• Public-facing page rendering
• Storage and retrieval of page-related data

Affected Fields

• Title
• URL
• Content
• Cover Image
• Image URL
• Image Width
• Image Height
• SEO Description
• SEO Keywords

Attack Scenario

• An attacker creates or edits a page and injects a malicious XSS payload into one or more page-related input fields.
• The application stores these values without sanitization or encoding.
• The payload is rendered in administrative page lists and public-facing page views.
• The payload executes automatically in the browser context of administrators, authenticated users, and unauthenticated visitors.

Impact

• Persistent Stored XSS
• Execution of arbitrary JavaScript in victims’ browsers
• Privilege escalation when viewed by administrators or privileged users
• Full administrator account takeover
• Full account takeover across all roles
• Full compromise of the entire application

Endpoints:

• /backend/pages/create
• Page list management view
• Public-facing page views

Steps To Reproduce (POC)

1. Navigate to the Page Management -> Add Page interface
2. Insert an XSS payload into any page-related field such as: <img src=x onerror=alert(document.domain)>
3. Save or publish the page
4. View the page via the administrative page list or public-facing page
5. Observe the XSS payload executing automatically

Remediation

• Avoid unsafe DOM manipulation methods: Do not use .html(), innerHTML, or similar sink functions in client-side JavaScript or server-side templating (e.g., PHP). Even when user input flowing into these sinks is not immediately apparent, they can introduce Cross-Site Scripting (XSS) vulnerabilities that an attacker may exploit.

• Apply output encoding: Implement HTML entity encoding on all user-controlled data before rendering it in the browser. This helps neutralize potentially malicious input.

• Implement input sanitization: Ensure that all user-supplied input is properly sanitized before processing or output. Currently, no sanitization mechanisms are in place, which should be addressed as a priority.

• Enforce security headers and cookie attributes:

  • Content Security Policy (CSP): Define and enforce a strict CSP to limit the execution of unauthorized scripts.
  • HttpOnly flag: Set the HttpOnly attribute on session cookies to prevent client-side script access.
  • SameSite attribute: Configure the SameSite cookie attribute to mitigate Cross-Site Request Forgery (CSRF) risks.
  • Secure flag: Ensure all cookies are transmitted only over HTTPS by enabling the Secure attribute.

  These measures collectively reduce the impact of XSS and help prevent escalation paths such as CSRF via XSS.

Ready Video POC:

https://mega.nz/file/iAkWAKQY#hCUv4DlMPFykPvb4gO94ZVGj64tpUk99gLxE6u1kASk