> For the complete documentation index, see [llms.txt](https://hacking-notes.jord4n.pro/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://hacking-notes.jord4n.pro/web/xss/reflected-xss-in-html-with-blocked-tags.md).
# XSS Reflected in HTML with Blocked Tags
XSS Reflected in HTML with Blocked Tags notes for PortSwigger Web Security Academy labs, including exploitation workflow, payload testing, Burp Suite validation, and remediation context.
### Reflected XSS Into HTML Context with Most Tags and Attributes Blocked
This lab contains a reflected XSS vulnerability in the search feature, but an Application Firewall (WAF) blocks the most common XSS vectors. / To solve the lab, you must bypass the WAF and trigger the `print()` function.
* Trying classic payloads like `
test
`, `test
* I intercepted the page with Burp Suite and launched a mailing via Intruder.
I copied the types of event attributes (event handlers) and tested several of them into the cheatsheet of portswigger.
* J
```
```
* I have filtered/tried several attributes of events and I have focused on `onresize`.
```javascript
```
Payload tested and operated:
* Direct injection: `` — by resize (zoom wheel) alert appears.
Final goal: Call `print()` instead of `alert()`:
```javascript
```
URL exploit sent to victim:
```javascript
https://0a8500230379f8e980d8032300850075.web-security-academy.net/?search=
```
Delivery via iframe and automatic trigger:
* To force the `onresize` event to load in the frame, the width of the frame is changed from its `onload` attribute:
{% code overflow="wrap" %}
```javascript
```
{% endcode %}
Summary: WAF bypass by injecting an authorized event attribute (`onresize`) that calls `print()`, then delivery via iframe with `onload` that changes the size to trigger `onresize`.
---
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