*Title:* Allied Telesis AT-RG634A ADSL Broadband router hidden administrative unauthenticated webshell. *Vulnerability Information:* - CVE: CVE-2014-1982 - Type of Vulnerability: - CWE-78 : OS Command Injection - CWE-306 : Missing Authentication for Critical Function *Affected products:* - Allied Telesis AT-RG634A ADSL Broadband router. (version 3.3+ and probably others) Other products like, - Allied Telesis iMG624A (firmware version, 3.5) - Allied Telesis iMG616LH (firmware version, +2.4) - Allied Telesis iMG646BD (firmware version, 3.5) *Vendor:* - Allied Telesis : http://www.alliedtelesis.com// has the same vulnerbility, but the vendor reports that the version 3.8.05 of the firmware has already addressed this issue, but we where unable to test nor confirm this information. *Security Patches / Workaround:* - Allied Telesis has noted that the AT-RG634A product is no longer supported, but gives a workaround to mitigate the issue. Configure the device so that only trusted devices can access the target device using the following command, "WEBSERVER SET MANAGEMENTIP <ip-address>" *Short Description:* The Allied Telesis AT-RG634A ADSL Broadband router has a hidden url page in their admnistrative HTTP interface capable of executing commands as admin without requiring any kind of authentication. *Description:* "The AT-RG634 is a full-featured, broadband media gateway and router designed for cost-effective delivery of advanced IP Triple Play voice, video and data services over an ADSL infrastructure. The RG634 supports Layer 3 functions, including NAT, DMZ, and Stateful inspection firewall for delivery of revenue-generating services such as home networking and security services." (from www.alliedtelesis.com/p-2345.html) The Allied Telesis AT-RG634A ADSL Broadband router has a hidden URL (/cli.html) page to execute CLI command with admin priviledges, available by default and without any kind of authentication. Having as impact a total compromise of the target device. *Steps to reproduce:* - Connect via HTTP to the hidden page http://<device IP>/cli.html a input box is shown, every command typed there will be executed as admin. Entering the following lines in the hidden page (/cli.html) a new telnet admin user called "eviluser" is added to the system. >> system add login eviluser system set user eviluser access >> superuser. *Credits:* This security issue was discovered and researched by Sebastian Muniz (topo), Security Researcher of Groundworks Technologies (http://www.groundworkstech.com) *License:* The contents of this advisory are copyright (c) 2014 Groundworks Technologies,and are licensed under a Creative Commons Attribution Non-Commercial Share-Alike 3.0 (United States) License: http://creativecommons.org/licenses/by-nc-sa/3.0/us/