Lucene search

K
securityvulnsSecurityvulnsSECURITYVULNS:DOC:4239
HistoryMar 20, 2003 - 12:00 a.m.

Microsoft Security Bulletin MS03-009: Flaw In ISA Server DNS Intrusion Detection Filter Can Cause Denial Of Service (331065)

2003-03-2000:00:00
vulners.com
18

-----BEGIN PGP SIGNED MESSAGE-----


Title: Flaw In ISA Server DNS Intrusion Detection Filter Can
Cause Denial Of Service (331065)
Date: 19 March 2003
Software: Microsoft ISA Server
Impact: Denial of Service
Max Risk: Moderate
Bulletin: MS03-009

Microsoft encourages customers to review the Security Bulletins at:
http://www.microsoft.com/technet/security/bulletin/MS03-009.asp
http://www.microsoft.com/security/security_bulletins/ms03-009.asp


Issue:

Microsoft Internet Security and Acceleration (ISA) Server 2000
contains the ability to apply application filters to incoming
traffic. Application filters allow ISA Server to analyze a data
stream for a particular application and provide application-
specific processing including inspecting, screening or blocking,
redirecting, or modifying the data as it passes through the
firewall. This mechanism is used to protect against invalid URLs
which may indicate attempted attacks as well as attacks against
internal Domain Name Service (DNS) Servers.

A flaw exists in the ISA Server DNS intrusion detection application
filter, and results because the filter does not properly handle a
specific type of request when scanning incoming DNS requests.

An attacker could exploit the vulnerability by sending a specially
formed request to an ISA Server computer that is publishing a DNS
server, which could then result in a denial of service to the
published DNS server. DNS requests arriving at the ISA Server would
be stopped at the firewall, and not passed through to the internal
DNS server. All other ISA Server functionality would be unaffected.

Mitigating Factors:

  • By default, no DNS servers are published. DNS server publishing

    must be manually enabled.

  • The vulnerability would not enable an attacker to gain any
    privileges on an affected ISA Server or the published DNS server
    or to compromise any cached content on the server. It is
    strictly a denial of service vulnerability.

Risk Rating:

  • Moderate

Patch Availability:

  • A patch is available to fix this vulnerability. Please read the
    Security Bulletins at

http://www.microsoft.com/technet/security/bulletin/ms03-009.asp
http://www.microsoft.com/security/security_bulletins/ms03-009.asp

for information on obtaining this patch.


THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS
PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS
ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE
FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL,
CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF
MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE
POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION
OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES
SO THE FOREGOING LIMITATION MAY NOT APPLY.

-----BEGIN PGP SIGNATURE-----
Version: PGP 7.1

iQEVAwUBPni3qo0ZSRQxA/UrAQGl3gf+LrKTjf5hyCV2b+qkEagre6zgb2CuOP+A
auPp73+kYOHiI5Bd8STtHSdeedevmui5EDWDIkWR9tWm45eDXuy4dLFU8N9qH+id
lVrL/61eJuJz/9W53PxSsCy2wAisYrXcRA9nl0TrBU3/2WApHY2AkcIXWieG/KBS
XIcZQ+1gNb5Go+i/vrhNhsQaJJcWf7ziKLks5SRtWYUPc947DYLGulFhc+FRzwnc
OxSxKVGgncg/nc/86cDLZVM1jGzYao78VloPQoIVNPfsBmjx6s3+x0oGzOKCJwNp
w/GWnDIK8usqPu62pQYsjVDViA7Rz5Piub+73gbwEX1ytri/FHPsgg==
=Uf5c
-----END PGP SIGNATURE-----


You have received this e-mail bulletin because of your subscription to the Microsoft Product Security
Notification Service. For more information on this service, please visit
http://www.microsoft.com/technet/security/notify.asp.

To verify the digital signature on this bulletin, please download our PGP key at
http://www.microsoft.com/technet/security/notify.asp.

To unsubscribe from the Microsoft Security Notification Service, please visit the Microsoft Profile
Center at http://register.microsoft.com/regsys/pic.asp

If you do not wish to use Microsoft Passport, you can unsubscribe from the Microsoft Security
Notification Service via email as described below:
Reply to this message with the word UNSUBSCRIBE in the Subject line.

For security-related information about Microsoft products, please visit the Microsoft Security Advisor
web site at http://www.microsoft.com/security.