connoppp.cgi on ZTE ZXDSL 831CII devices does not require HTTP Basic Authentication, which allows remote attackers to modify the PPPoE configuration or set up a malicious configuration via a GET request.

Multiple cross-site request forgery (CSRF) vulnerabilities in ZTE ZXDSL 831CII allow remote attackers to hijack the authentication of administrators for requests that (1) change the admin user name or (2) conduct cross-site scripting (XSS) attacks via the sysUserName parameter in a save action to adminpasswd.cgi or (3) change the admin user password via the sysPassword parameter in a save action to adminpasswd.cgi.

Cross-site scripting (XSS) vulnerability in the Quick Stats page (psilan.cgi) in ZTE ZXDSL 831 and 831CII allows remote attackers to inject arbitrary web script or HTML via the domainname parameter in a save action. NOTE: this issue was SPLIT from CVE-2014-9021 per ADT1 due to different affected products and codebases.

ZTE ZXDSL 831CII has a default password of admin for the admin account, which allows remote attackers to gain administrator privileges.

ZTE ZXDSL 831CII allows remote attackers to bypass authentication via a direct request to (1) main.cgi, (2) adminpasswd.cgi, (3) userpasswd.cgi, (4) upload.cgi, (5) conprocess.cgi, or (6) connect.cgi.

Cross-site request forgery (CSRF) vulnerability in accessaccount.cgi in ZTE ZXDSL 831IIV7.5.0a_Z29_OV allows remote attackers to hijack the authentication of administrators for requests that change the administrator password via the sysPassword parameter.