Old issue- MS NT PPTP/RAS DoS

[SanjayR <sanjayr () intoto com>]

Hi..

Sorry for posting a mail on a very old issue. but still, I shall 
appreciate, if somebody responds to this.

While analyzing some vulnerability, and doing some back tracing, I came to 
know about one issue of DoS on Microsoft NT RAS/PPTP. The issue is covered 
under BID 2111 and has CVE-1999-0140. the description says that if we 
telnet to MS NT box on port 1723 and send some junk data of length ~256 
followed by ctrl-d, the NT box reboots. My doubt is, does this DoS occur 
due to sending data + ctrl-d ? ctrl-d is for EOT, therefore, it should not 
reach NT box as such. Only the FIN packet will go. I looked into the PPTP 
header. There is one field, called "magic cookie", whose value is fix as 
0x1A2B3C4D. But when we send junk data, this value also gets changed 
(because we are not sending data in PPTP format). My question is: is this 
the cause of attack (i.e. changed value of cookie) or the earlier one, 
mentioned everywhere?

thanks in advance for everyone who will spare their time to reply this.

regards
-Sanjay