Rule:

--
Sid:
1226

--
Summary:
This event is generated when an attempt to launch an X windows application on an X windows server is made.

--
Impact:
Possible theft of data and control of the targeted machine leading to a compromise of all resources the machine is connected to.

--
Detailed Information:
Implementations of the X windows system from the X consortium may use weak authentication methods when allowing remote machines to connect to a host running X windows.

XDM is used to allow remote users access to the remote X window server. When configured incorrectly, this may allow an unathorised user to connect to the display.

This event is generated when a user outside the protected network opens an X windows application on the remote X server.

--
Attack Scenarios:
The remote attacker may scan the host for listening X window servers, then connect to the remote host using XDM. The attacker may then execute an X windows application on the remote host.

--
Ease of Attack:
Simple.

--
False Positives:
None Known

--
False Negatives:
None Known

--
Corrective Action:
Disallow connections to X servers from hosts outside the protected network.

Apply the appropriate vendor patches.

Upgrade to the latest version of the software.

--
Contributors:
Original Rule Writer Max Vision <vision@whitehats.com>
Sourcefire Research Team
Nigel Houghton <nigel.houghton@sourcefire.com>

--
Additional References:

Whitehats arachNIDS
http://www.whitehats.com/info/IDS396

--
