Denial of Service in Microsoft Directory Services Port 445

Reported April 17, 2002, by Peter Gründl.

VERSIONS AFFECTED

• Windows 2000 Advanced Server Service Pack 1 (SP1) and SP2

• Windows 2000 Server SP1 and SP2

• Windows 2000 Professional SP1 and SP2

 

DESCRIPTION

A Denial of Service (DoS) condition exists in Microsoft’s Directory Services running on TCP port 445. An attacker sending a large stream of null characters or malformed characters to the service can freeze the system because of CPU and kernel-resource depletion or, in some cases, can cause a blue screen.

VENDOR RESPONSE

 

The vendor, Microsoft, has released two workarounds that mitigate this vulnerability.

 

CREDIT
Discovered by Peter Gründl.