GHSA-x7wh-g25g-53vg

## Summary ### **Vulnerability: Stored DOM XSS via Blog Post Content (Persistent Payload Injection)** - Stored Cross-Site Scripting via Unsanitized Blog Post Content in Blog Management

### Description The application fails to properly sanitize user-controlled input when creating or editing blog posts. An attacker can inject a malicious JavaScript payload into blog post content, which is then stored server-side.

This stored payload is later rendered unsafely in multiple application views without proper output encoding, leading to stored cross-site scripting (XSS).

### Affected Functionality - Blog post creation functionality - Blog post editing functionality - Blog post storage and retrieval logic

### Attack Scenario - An attacker creates or edits a blog post to include a malicious XSS payload. - The application stores this content without sanitization or encoding. - The payload persists and executes whenever the blog post 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/create` - `/backend/blogs/` - `/blog/{id}`

## Steps To Reproduce (POC) 1. Go to the Blog Post Create or Edit page 2. Insert an XSS payload into the blog post content such as: `<img src=x onerror=alert(document.domain)>` 3. Save or publish the blog post 4. View the post via the administrative panel or public blog page 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/bYtCQRqT#ph1S_01XaYXiNTzanP3AVL6aQMe0YC5Py7Gko1FoT4A