Citrix Provisioning Services Buffer Overflow

July 8, 2011

Citrix Provisioning Services is a workload (operating system, application, and configuration) management system. It maximizes flexibility of hardware resources by making no software preloaded on the systems; instead, computers will obtain application from the network in real-time. A proprietary communication protocol is used between the Provisioning Server and other components.

Several buffer overflow vulnerabilities exist in the Citrix Provisioning Services. Specifically, the vulnerabilities are due to insufficient validation of data sent to the streamprocess.exe, which listens on port 6905/udp. An attacker can exploit these vulnerabilities by sending crafted packets to the target server. Successful exploitation would allow for arbitrary code injection and execution with the privileges of the streamprocess.exe. Code injection that does not result in execution would terminate the service due to memory corruption.

SonicWALL has released several IPS signatures to detect and block known exploits targeting these vulnerabilities. The signatures are listed below:

  • 6346 - Citrix Provisioning Services Buffer Overflow 1
  • 6794 - Citrix Provisioning Services Buffer Overflow 2