XSS Stored — تزریق اسکریپت دائمی در وب‌اپلیکیشن

Stored XSS is one of the most impactful client-side vulnerabilities, allowing persistent script injection that executes in every victim's browser.

## Vulnerability Overview
Stored (Persistent) XSS occurs when malicious scripts are saved to the server (database, files) and later rendered in other users' browsers without proper encoding. Unlike Reflected XSS, no phishing link is needed — the payload executes automatically when the victim visits the affected page.

## Technical Details
- **Vulnerable Component:** Comment sections, user profiles, forum posts, product reviews
- **Root Cause:** Lack of output encoding when rendering user-supplied content in HTML context
- **Payload Execution:** Every user who views the infected page executes the attacker's JavaScript
- **Escalation:** Can be chained with CSRF to perform admin actions, or used for BeEF browser exploitation

## Impact Assessment
- Session cookie theft → account takeover
- Keylogging and credential harvesting
- Redirecting users to phishing pages
- Drive-by malware distribution
- Admin account compromise leading to full site takeover
- Defacement

## Affected Versions
- WordPress < 6.5.2 (PDF.js XSS via media upload)
- Any application rendering unsanitized user input in HTML

## Indicators of Compromise
- Unexpected <script> tags in database content
- Unusual outbound requests to attacker-controlled domains in server logs