ZyXEL Prestige routers, including P-660 and P-661 models with firmware 3.40(AGD.2) through 3.40(AHQ.3), have (1) "user" as their default password for the "user" account and (2) "1234" as their default password for the "admin" account, which makes it easier for remote attackers to obtain access.

More... (http://nvd.nist.gov/nvd.cfm?cvename=CVE-2008-1522)