The Linksys WRT54G router has "admin" as its default FTP password, which allows remote attackers to access sensitive files including nvram.cfg, a file that lists all HTML documents, and an ELF executable file.
https://exchange.xforce.ibmcloud.com/vulnerabilities/41126
http://www.securityfocus.com/archive/1/489009/100/0/threaded
http://www.gnucitizen.org/projects/router-hacking-challenge/