### [CVE-2017-7783](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-7783)
![](https://img.shields.io/static/v1?label=Product&message=Firefox&color=blue)
![](https://img.shields.io/static/v1?label=Version&message=%3C%2055%20&color=brighgreen)
![](https://img.shields.io/static/v1?label=Vulnerability&message=DOS%20attack%20through%20long%20username%20in%20URL&color=brighgreen)

### Description

If a long user name is used in a username/password combination in a site URL (such as " http://UserName:Password@example.com"), the resulting modal prompt will hang in a non-responsive state or crash, causing a denial of service. This vulnerability affects Firefox < 55.

### POC

#### Reference
- https://bugzilla.mozilla.org/show_bug.cgi?id=1360842
- https://www.exploit-db.com/exploits/43020/

#### Github
No PoCs found on GitHub currently.