def-2001-17: Navision Financials Server DoS Published: Tue Apr 03 2001 Updated: Tue Apr 03 2001 ====================================================================== Defcom Labs Advisory def-2001-17 Navision Financials Server DoS Author: Peter Gründl Release Date: 2001-04-03 ====================================================================== ------------------------=[Brief Description]=------------------------- The Navision Financials Server contains a flaw that allows an attacker to crash the service. ------------------------=[Affected Systems]=-------------------------- - Navision Financials Server V2.50 for Windows NT/2000 - Navision Financials Server V2.60 for Windows NT/2000 ----------------------=[Detailed Description]=------------------------ Sending a null character followed by approx. 30k of A's to TCP port 2407 causes a buffer overflow and terminates the process (SERVER.EXE). The overflow does not appear to be exploitable. A smaller amount can also be used, and will silently kill the process. This requires approx. 10 connections starting with a null character, followed by 100+ characters. ---------------------------=[Workaround]=----------------------------- Disallow access to TCP port 2407 from untrusted systems, and contact Navision-Damgaard Support to obtain the patch for this problem: http://www.navision.com/com/view.asp?documentID=258 -------------------------=[Vendor Response]=-------------------------- The issue was brought to the vendors attention on the 21st of December, 2000. A patch was created by the vendor on the 5th of March, 2001. ====================================================================== This release was brought to you by Defcom Labs labs@defcom.com www.defcom.com