There is a great article about VxWorks OS vulnerabilities at Metasploit Blog.
Back in June, I decided to spend some time looking at the VxWorks operating system. Specifically, I kept finding references to VxWorks-based devices running firmware images with the debug service (WDB Agent) enabled, but I could not find a description of the protocol or any estimates as to how prevalent this service was. After a couple days of digging around and a couple more days of scanning, I became aware of just how extensive this issue is.
For folks who aren’t aware of what VxWorks is — VxWorks was the most popular embedded operating system in 2005, it is a platform developed by Wind River Systems, which has since been acquired by Intel. Vendors who wish to build products using the VxWorks operating system will license it out by component, integrate their own application code, and then build images which can be installed on their products. VxWorks has been used to power everything from the Apple Airport Extreme access points to the Mars rovers and the C-130 Hercules aircraft. VxWorks itself is essentially a monolithic kernel with applications implemented as kernel tasks. This means that all tasks generally run with the highest privileges and there is little memory protection between these tasks (at least with version 5.x).
The WDB agent is a system-level debugger for the VxWorks operating system that runs on UDP port 17185. This service is modeled on the SunRPC protocol in terms of wire format and allows anyone with access to this port to read memory, write memory, call functions, and manage tasks. Since the protocol is UDP and there is no authentication, handshake, or session ID, requests to the WDB agent can also be spoofed by an attacker.
To determine how widespread this issue was, I wrote a scanner module for the Metasploit Framework and conducted a network survey that encompassed over 3.1 billion IP addresses. Of this set, over 250,000 systems were found with the WDB agent exposed. After digging around in the DShield database, it became obvious that an unknown party had already spent most of 2006 scanning for this service. I contacted the Carnegie Mellon CERT and provided them with the list of affected devices that were gleaned from the survey, with the goal of notifying as many vendors as possible in a reasonable amount of time. CERT assigned VU#362332 to this issue and plans to publish an advisory today (August 2nd, 2010). The Rapid7 NeXpose engineering team has created a check for this vulnerability and made this available through the standard product update mechanism.
Read complete article at : http://blog.metasploit.com/2010/08/vxworks-vulnerabilities.html
Source: [Metasploit Blog]