Summary

Vulnerability: Stored DOM XSS via Blog Category Title (Persistent Payload Injection)

• Stored Cross-Site Scripting via Unsanitized Blog Category Title in Blog Management

Description

The application fails to properly sanitize user-controlled input when creating or editing blog categories. An attacker can inject a malicious JavaScript payload into the category title field, which is then stored server-side.

This stored payload is later rendered unsafely across public-facing blog category pages, administrative interfaces, and blog post views without proper output encoding, leading to stored cross-site scripting (XSS).

Affected Functionality

• Blog category creation functionality
• Blog category editing functionality
• Blog category storage and retrieval logic

Attack Scenario

• An attacker creates or edits a blog category title to include a malicious XSS payload.
• The application stores this value without sanitization or encoding.
• The payload persists and executes whenever the category title is rendered in affected views.

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/blogs/categories/
• /blog/{id}

Steps To Reproduce (POC)

1. Go to the Blog Categories management page
2. Create or edit a category and insert an XSS payload into the category title such as:
   <img src=x onerror=alert(document.domain)>
3. Save the category
4. View a public blog category page, blog post page, or the administrative interface
5. Notice 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/GAFC3AJY#3LHyuyl7I7921UEeA-JlUYdckh6zGLCTy-6w9BNzSmQ

References

• GHSA-fhrf-q333-82fm