Related Vulnerabilities: CVE-2017-7783  

A denial of service has been found in Firefox < 55.0. 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.

Severity Low

Remote Yes

Type Denial of service

Description

A denial of service has been found in Firefox < 55.0. 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.

AVG-375 firefox 54.0.1-1 55.0-1 Critical Fixed

10 Aug 2017 ASA-201708-3 AVG-375 firefox Critical multiple issues

https://www.mozilla.org/en-US/security/advisories/mfsa2017-18/#CVE-2017-7783
https://bugzilla.mozilla.org/show_bug.cgi?id=1360842