The Zyxel P-2602HW-D1A router with 3.40(AJZ.1) firmware maintains authentication state by IP address, which allows remote attackers to bypass authentication by establishing a session from a source IP address of a user who previously authenticated within the previous 5 minutes.

Cross-site scripting (XSS) vulnerability in Forms/DiagGeneral_2 on the ZyXEL P-660HW series router allows remote attackers to inject arbitrary web script or HTML via the PingIPAddr parameter.

The ZyXEL P-660HW series router maintains authentication state by IP address, which allows remote attackers to bypass authentication by establishing a session from a source IP address of a previously authenticated user.

Multiple cross-site request forgery (CSRF) vulnerabilities on the ZyXEL P-660HW series router allow remote attackers to (1) change DNS servers and (2) add keywords to the "bannedlist" via unspecified vectors.

ZyXEL ZyWALL 1050 has a hard-coded password for the Quagga and Zebra processes that is not changed when it is set by a user, which allows remote attackers to gain privileges.

The ZyXEL P-660HW series router has "admin" as its default password, which allows remote attackers to gain administrative access.

Multiple cross-site request forgery (CSRF) vulnerabilities in the web management interface in the ZyXEL P-330W router allow remote attackers to hijack the authentication of administrators for requests that (1) enable remote router management via goform/formRmtMgt or (2) modify the administrator password via goform/formPasswordSetup.

Cross-site scripting (XSS) vulnerability in the web management interface in the ZyXEL P-330W router allows remote attackers to inject arbitrary web script or HTML via the pingstr parameter and other 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.

The Zyxel P-2602HW-D1A router with 3.40(AJZ.1) firmware provides different responses to admin page requests depending on whether a user is logged in, which allows remote attackers to obtain current login status by requesting an arbitrary admin URI.

ZyXEL Prestige routers have a minimum password length for the admin account that is too small, which makes it easier for remote attackers to guess passwords via brute force methods.

Cross-site scripting (XSS) vulnerability in Forms/General_1 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.

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/General_1 with the (1) sysSystemName and (2) sysDomainName parameters.

ZyXEL Prestige routers, including P-660, P-661, and P-662 models with firmware 3.40(PE9) and 3.40(AGD.2) through 3.40(AHQ.3), do not use a salt when calculating an MD5 password hash, which makes it easier for attackers to crack passwords.

The default SNMP configuration on ZyXEL Prestige routers, including P-660 and P-661 models with firmware 3.40(AGD.2) through 3.40(AHQ.3), has a Trusted Host value of 0.0.0.0, which allows remote attackers to send SNMP requests from any source IP address.

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.

ZyXEL Prestige routers, including P-660, P-661, and P-662 models with firmware 3.40(PE9) and 3.40(AGD.2) through 3.40(AHQ.3), support authentication over HTTP via a hash string in the hiddenPassword field, which allows remote attackers to obtain access via a replay attack.

ZyXEL Prestige routers, including P-660, P-661, and P-662 models with firmware 3.40(AGD.2) through 3.40(AHQ.3), allow remote authenticated users to obtain authentication data by making direct HTTP requests and then reading the HTML source, as demonstrated by a request for (1) RemMagSNMP.html, which discloses SNMP communities; or (2) WLAN.html, which discloses WEP keys.

The SNMP service on ZyXEL Prestige routers, including P-660 and P-661 models with firmware 3.40(AGD.2) through 3.40(AHQ.3), has "public" as its default community for both (1) read and (2) write operations, which allows remote attackers to perform administrative actions via SNMP, as demonstrated by reading the Dynamic DNS service password or inserting an XSS sequence into the system.sysName.0 variable, which is displayed on the System Status page.

ZyXEL Prestige routers, including P-660, P-661, and P-662 models with firmware 3.40(AGD.2) through 3.40(AHQ.3), allow remote authenticated users to obtain ISP and Dynamic DNS credentials by sending a direct request for (1) WAN.html, (2) wzPPPOE.html, and (3) rpDyDNS.html, and then reading the HTML source.