The popup blocker in Mozilla Firefox before 1.5.0.7 opens the "blocked popups" display in the context of the Location bar instead of the subframe from which the popup originated, which might make it easier for remote user-assisted attackers to conduct cross-site scripting (XSS) attacks.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.021
EPSS Ranking 83.5%