# XSS on error page

While I was looking for Business Logic Flaws on this target, I wondered what the response would be if I provided the wrong credentials.

When I entered the wrong credential, an error page appeared along with a message "Invalid Username/Password"\
\
The URL looked like : <https://example.com/login?errorCd=views.login.email.password.required\\>
So I tampered the parameter to XSS payloads. However, the payloads were not executing.

\
I then tried SSTI payloads and one of them got executed. The final PoC link looked like:\
<https://example.com/login?errorCd=\\{{2\\*2\\}}\\>
and the error message displayed "4"<br>

I reported it under Client Side Template Injection but later it was categorized by the triager as XSS 🤷‍♂️.<br>


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