Software Engineering Institute

Novell eDirectory iMonitor is a service for monitoring servers in an eDirectory installation. A buffer overflow exists in Novell eDirectory version 8.7.3 iMonitor for Microsoft Windows 2000, 2003, and NT. A stack-based buffer within the iMonitor can be overwritten via a specially-crafted HTTP request. To exploit this vulnerability an attacker must have access to iMonitor which is installed on systems that are part of a Novell eDirectory tree.

Note that exploits for this vulnerability have been made available on public web sites.

A remote attacker with access to a system in a Novell eDirectory tree may be able to crash an affected system or execute arbitrary code with the privileges of the iMonitor service, typically SYSTEM on Microsoft Windows.

Apply a patch
Novell has released the patch (edir873ptf_imon1.exe) to correct this issue.

Restrict access

To limit your exposure to attacks you may wish to block access to Novell iMonitor from outside your network perimeter. However, blocking at the network perimeter would still allow attackers within the perimeter of your network to exploit the vulnerability. The use of host-based firewalls in addition to network-based firewalls can help restrict access to specific hosts within the network. It is important to understand your network's configuration and service requirements before deciding what changes are appropriate.