Local / Remote D.o.S Attack in Serv-U FTP-Server v2.5b for Win9x/WinNT Vulnerability

   

Serv-u

Serv-U FTP-Server v2.5x and maybe other versions.

Binary D.O.S

dserv25b.exe

link.bro

For the executable

Source of Binary D.O.S

dserv25b.zip


USSR Advisory Code:   USSR-2000032


Release Date:
February 04, 2000


Systems Affected:
Serv-U FTP-Server v2.5b and maybe other versions.
Windows 95
Windows 98
Windows Nt 4.0 WorkStation
Windows Nt 4.0 Server

THE PROBLEM
UssrLabs found a buffer overflow, in one Windows Api "SHGetPathFromIDList" This function 
converts an item identifier list to a file system path, just one Api who manage Links
files under windows.
If you have one malformed link file you can crash anything who try to Translate from 
.lnk file like EXPLORER.EXE. all common dialogs and so on (copy one malformed link 
file to the desktop,and you cant login intro the machine).
To made Serv-u crash just upload one malformed link file in any serv-u 
directory and type the ftp command LIST, and Server Crashh.

Note:
 this overflow no work under win2k

Example Malformed link in: http://www.ussrback.com/god.lnk

Vendor Status:
Contacted.

Vendor   Url:  http://ftpserv-u.deerfield.com/
Program Url: http://ftpserv-u.deerfield.com/download.cfm

Credit: USSRLABS

SOLUTION
    Next version, personal code for handle links files.

Greetings:
Eeye, Attrition, w00w00, beavuh, Rhino9, ADM, L0pht, HNN, Technotronic and
Wiretrip.