ZyXEL P-660HW-T1 2 devices with ZyNOS firmware 3.40(AXH.0), PMG5318-B20A devices with firmware 1.00AANC0b5, and NBG-418N devices have a default password of 1234 for the admin account, which allows remote attackers to obtain administrative access via unspecified vectors.

The management interface in ZyNOS firmware 3.62(WK.6) on the Zyxel Zywall 2 device allows remote authenticated administrators to cause a denial of service (infinite reboot loop) via invalid configuration data. NOTE: this issue might not cross privilege boundaries, and it might be resultant from CSRF; if so, then it should not be included in CVE.

Multiple cross-site request forgery (CSRF) vulnerabilities in the management interface in ZyNOS firmware 3.62(WK.6) on the Zyxel Zywall 2 device allow remote attackers to perform certain actions as administrators, as demonstrated by a request to Forms/General1 with the (1) sysSystemName and (2) sysDomainName parameters.

Cross-site scripting (XSS) vulnerability in Forms/General1 in the management interface in ZyNOS firmware 3.62(WK.6) on the Zyxel Zywall 2 device allows remote authenticated administrators to inject arbitrary web script or HTML via the sysSystemName parameter.

The management interface in ZyNOS firmware 3.62(WK.6) on the Zyxel Zywall 2 device has a certain default password, which allows remote attackers to perform administrative actions.

ZynOS 3.40 allows remote attackers to cause a denial of service (link restart) by sending a request for the name \M via the SMB Mail Slot Protocol.

ZyXEL Prestige 623, 650, and 652 HW Routers, and possibly other versions, with HTTP Remote Administration enabled, does not require a password to access rpFWUpload.html, which allows remote attackers to reset the router configuration file.

Zyxel P681 running ZyNOS Vt020225a contains portions of memory in an ARP request, which allows remote attackers to obtain sensitive information by sniffing the network.