-----BEGIN PGP SIGNED MESSAGE----- =============================================================================== Security Advisory CERT-NL =============================================================================== Author/Source : Egon Verharen Index : S-99-21 Distribution : World Page : 1 Classification: External Version: 1 Subject : Unauthorized Access to IIS Servers through ODBC Data Access with RDS Date : 19-Jul-99 =============================================================================== By courtesy of MICROSOFT we received information on Unauthorized Access to IIS Servers through ODBC Data Access with RDS CERT-NL recommends reading the advisory carefully since many systems are affected by this vulnerability and apply the provided patches. Please also read the mail from the NTBugTraq maintainer on this: http://www.ntbugtraq.com/default.asp?pid=36&sid=1&A2=ind9907&L=ntbugtraq&F=P&S=&P= 6761 (LINE WRAPPED !) ============================================================================== Microsoft Security Bulletin (MS99-025) - -------------------------------------- Re-Release: Unauthorized Access to IIS Servers through ODBC Data Access with RDS Originally Released as MS98-004, July 17, 1998 Re-Released as MS99-025, July 19, 1999 Preface ======= This bulletin is a re-release of Microsoft Security Bulletin MS98-004, issued July 17, 1998. It has recently been brought to our attention that this vulnerability has been used to gain unauthorized access to Internet-connected systems that have not been updated as per the instructions in MS98-004. The intent of re-releasing this bulletin is to serve as a reminder about this vulnerability, to restate the threat, and encourage system administrators to evaluate their systems to determine if their systems have been correctly configured and updated to protect against this vulnerability. Summary ======= Microsoft encourages the following actions be taken on systems that have Microsoft(r) Internet Information Server 3.0 or 4.0 and Microsoft Data Access Components 1.5, both of which are installed during a default installation of the Windows NT(r) 4.0 Option pack: - Install the latest version of MDAC (currently MDAC 2.1 SP2). However, simply upgrading from MDAC 1.5 to MDAC 2.0, or MDAC 2.1 is not sufficient. For systems not explicitly utilizing RDS functionality, you should also: - Delete the /msdac virtual directory from the default Web site, or - Apply registry settings that disable the DataFactory object. (See the Q&A for the registry settings to adjust, or to download a .REG file that can make the changes for you.) For systems implicitly utilizing RDS functionality, you should: - Disable Anonymous Access for the /msadc directory in the default Web site, and/or - Create a Custom Handler to control or filter incoming requests. (http://www.microsoft.com/Data/ado/rds/custhand.htm) If you do not complete these steps, unauthorized access as described below may still be possible. Frequently asked questions regarding this vulnerability and updating systems to protect against it can be found at http://www.microsoft.com/security/bulletins/MS99-025faq.asp Issue ===== The RDS DataFactory object, a component of Microsoft Data Access Components (MDAC), exposes unsafe methods. When installed on a system running Internet Information Server 3.0 or 4.0, the DataFactory object may permit an otherwise unauthorized web user to perform privileged actions, including: - Allowing unauthorized users to execute shell commands on the IIS system as a privileged user. - On a multi-homed Internet-connected IIS system, using MDAC to tunnel SQL and other ODBC data requests through the public connection to a private back-end network. - Allowing unauthorized accessing to secured, non-published files on the IIS system. Affected Software Versions ========================== - Microsoft Internet Information Server 3.0 or 4.0 that have or have had Microsoft Data Access Components 1.5 installed on it. NOTE: IIS can be installed as part of other Microsoft products like Microsoft BackOffice and Microsoft Site Server. NOTE: MDAC 1.5 is installed during a default installation of the Windows NT 4.0 Option Pack. Patch Availability ================== Newer versions of Microsoft Data Access Components (MDAC versions 2.0 and 2.1) resolve these known vulnerabilities. However, a system that had MDAC 1.5 installed on it, and then upgraded to MDAC 2.0 or MDAC 2.1 must still take actions to disable the DataFactory object. (See the Q&A for the registry settings to adjust, or to download a .REG file that can make the changes for you.) Current versions of Microsoft Data Access Components can be downloaded from the following web site: - Microsoft Data Access Download Site (http://www.microsoft.com/data/download.htm) More Information ================ Please see the following references for more information related to this issue. - Microsoft Security Bulletin MS99-025: Frequently Asked Questions, http://www.microsoft.com/security/bulletins/MS99-025faq.asp - Microsoft Knowledge Base (KB) article Q184375, Security Implications of RDS 1.5, IIS, and ODBC, http://support.microsoft.com/support/kb/articles/q184/3/75.asp - Microsoft Universal Data Access Download Page, http://www.microsoft.com/data/download.htm - Installing MDAC Q&A, http://www.microsoft.com/data/MDAC21info/MDACinstQ.htm - Microsoft Security Advisor web site, http://www.microsoft.com/security/default.asp - IIS Security Checklist, http://www.microsoft.com/security/products/iis/CheckList.asp Obtaining Support on this Issue =============================== Microsoft Data Access Components (MDAC) is a fully supported set of technologies. If you require technical assistance with this issue, please contact Microsoft Technical Support. For information on contacting Microsoft Technical Support, please see http://support.microsoft.com/support/contact/default.asp. Acknowledgments =============== Microsoft acknowledges Greg Gonzalez of ITE (http://www.infotechent.net) for bringing additional information regarding this vulnerability to our attention. Microsoft also acknowledges Russ Cooper (NTBugTraq) for his assistance around this issue. Revisions ========= - July 19, 1999: Bulletin Created as re-release of MS98-004. ============================================================================== CERT-NL is the Computer Emergency Response Team for SURFnet customers. SURFnet is the Dutch network for educational, research and related institutes. CERT-NL is a member of the Forum of Incident Response and Security Teams (FIRST). 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