SECURITY.NNO: FTGate PRO/Office hotfixes

From: 3APA3A (3APA3Aat_private)
Date: Wed Apr 03 2002 - 08:18:26 PST

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    Dear bugtraq,
    
    Original version available at http://www.security.nnov.ru/advisories/ftgate.asp
    
    Title                   : FTGate PRO/Office hotfixes
    Author                  : 3APA3A <3APA3Aat_private>
    Date                    : December, 18 2001
    Affected                : FTGate PRO 1.05, FTGate Office 1.05
    Vendor                  : Floositek [1]
    Risk                    : high
    Remote                  : yes
    Exploitable             : yes
    
    Intro:
    
    Ftgate  is Internet mail server for Windows with SMTP/POP3 support and a
    lot   of   additional  features  by  Floositek[1].  During  testing  few
    vulnerabilities   were   found  by  Ilya  Teterin  aka  buggzy  [4]  and
    SECURITY.NNOV [3].
    
    Details:
    
    1. Heap overflow in APOP command
    
    FTGate  detects  buffer  overflow  attack  attempts.  If attack detected
    source  IP  is  banned. But in case of APOP command it still possible to
    overflow dynamic buffer with
    
     APOP USER <BUFFER>
    
    it  causes  program  to crash immediately or after buffer is free()'d if
    buffer  size  is  in  range of approximately 1-2k. FTGateSrv.exe crashes
    with message like
    
          FTGateSrv.exe - Application error
    
          The instruction at 0x002b686b referenced memory at 0x41414145. The
          memory couldn't be "read".
    
          002B6865   mov         edx,dword ptr [ebp-20h]
          002B6868   mov         eax,dword ptr [edx+4]
          002B686B   call        dword ptr [eax+4]
    
    (as you can see in example this problem can be exploited to execute code
    of attacker's choice, but there are few different crash situations. It's
    not clear if this problem can always be exploited remotely.)
    
    2. DoS via Rcpt to: flood
    
    By  specifying  huge number of Rcpt to: in SMTP session it's possible to
    cause  memory leak. During and after attack server will use 100% CPU.
    
    3. DoS against POP3 mailbox.
    
    As  reported  by  buggzy [4] mailbox can be locked before authentication
    via POP3 USER command.
    
    Vendor:
    
    Vendor  released  patches for FTGate PRO and FTGate Office [2] within 24
    hours after problem was committed.
    
    References:
    
    1. Floositek Ltd
       http://www.floositek.com
    2. Hotfixes for FTGatePro V1.05
       http://www.ftgate.com/knwldgbs/hotfix.htm
    3. Multiple bugs in FTGate
       http://www.security.nnov.ru/search/news.asp?binid=1884
    4. Головоломка для хакера, взлом FTGate 
       http://securitylab.ru/?ID=29407
    
    
    -- 
    http://www.security.nnov.ru
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