Cross-site scripting (XSS) vulnerability in the WebAAA login functionality (wba_login.html) in Juniper Networks Mobility System Software (MSS) 7.6.x before 7.6.3, 7.7.x before 7.7.1, 7.5.x before 7.5.3, and other unspecified versions before 7.4 and 7.3 allows remote attackers to inject arbitrary web script or HTML via a crafted parameter name.