The default configuration of IOS HTTP server in Cisco Router Web Setup (CRWS) before 3.3.0 build 31 does not require credentials, which allows remote attackers to access the server with arbitrary privilege levels, aka bug CSCsa78190.
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A5826
https://exchange.xforce.ibmcloud.com/vulnerabilities/27688
http://www.vupen.com/english/advisories/2006/2773
http://www.securityfocus.com/bid/18953
http://www.kb.cert.org/vuls/id/205225
http://www.cisco.com/warp/public/707/cisco-sa-20060712-crws.shtml