> 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/csrf/csrf-token-tied-to-non-session-cookie.md).
# CSRF with Token Tied to a Cookie but not to the Session
CSRF with Token Tied to a Cookie but not to the Session notes for PortSwigger Web Security Academy labs, including exploitation workflow, payload testing, Burp Suite validation, and remediation contex
### CSRF Where Token Is Tied to Non-session Cookie
The email change feature is vulnerable to CSRF. It uses chips, but they are not fully integrated into the session mechanism. Accounts provided: `wiener:peter` and `carlos:montoya`.
### Key Idea
* There is a `csrfKey` cookie and a `CSRF` query parameter for the change of email. Both values are "synchronized", but **not session-related**.
* By copying the pair (`csrfKey`, `CSRF`) from one account to another, one can change the email of one victim **without** that it is linked to its session.
* The search field saves the last search in a session cookie (`last searchTerm`).
#### Technical (CRLF Injection via Research)
* One can **inject headers** via the search to force the browser to set an arbitrary cookie.
A simple string like `hello csrfKey=aZCI...` is not interpreted.
```
hello csrfKey=aZCI65XauInHYlpP2MXHzMAssSvvyn74
```
On the other hand, with **back cart + line jump** (`/r` = `%0d`, `/n` = `%0a`):
```
man ascii
```
Working example:
```
hello%0d%0aSet-Cookie:%20csrfKey=a
```
→ interpreted as a **Set-Cookie** on the answer side.
For a cross-site context, specify `SameSite=none` for the cookie to accompany the next query since the exploit.
Example (in the address/search request bar):
{% code overflow="wrap" %}
```
hello%0d%0aSet-Cookie:%20csrfKey%3dGI0PraUBw0m976F6vn51dbYYzh6EtwvZ%3b%20SameSite%3dnone
hello
Set-Cookie: csrfKey=GI0PraUBw0m976F6vn51dbYYzh6EtwvZ; SameSite=none
```
{% endcode %}
### Hosted Operator
1. **Forcing** the `csrfKey` cookie in the victim via an image request to the search page (which rewrites the header):
```html
```
---
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