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-----BEGIN PGP SIGNED MESSAGE----- =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2001.244 -- ISS Security Advisory Oracle Redirect Denial of Service 20 June 2001 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: Oracle Vendor: Oracle Operating System: Windows NT Impact: Denial of Service Access Required: Remote - --------------------------BEGIN INCLUDED TEXT-------------------- - -----BEGIN PGP SIGNED MESSAGE----- Internet Security Systems Security Advisory June 19, 2001 Oracle Redirect Denial of Service Synopsis: Internet Security Systems (ISS) X-Force has identified a vulnerability with redirected Oracle connections. This vulnerability allows an unauthenticated user to consume all the memory on an Oracle server. It is also possible for remote users to deny access to all other users and cause the operating system to crash. Affected Versions: This issue is found on all versions of Oracle on Windows NT. Impact: This vulnerability causes a Windows NT system to consume 100% of available memory. Access to the server is denied and a full reboot is required. Description: For Oracle on Windows NT, the Oracle listener process redirects connection requests to a new port and the Oracle Database server creates a new thread for this port. If a connection to the port is not made, the thread and consumed memory is lost until the Oracle Database server is restarted. By repeatedly requesting to be redirected and not connecting to the waiting port, an Oracle server can be forced into consuming all memory on the server. Once all memory has been consumed on the server, any attempt to log in to the console results in crashing the operating system. Recommendations: There is an immediate workaround for this security vulnerability. Oracle Net8 (formerly Oracle SQL*Net) has a feature called “valid node checking” that can be used to allow or deny access to Oracle server processes from network clients with specified IP addresses. The following parameters can be established in PROTOCOL.ORA, a configuration file of Oracle Net8 to implement the valid node checking feature: tcp.validnode_checking = YES tcp.invited_nodes = {list of IP addresses} tcp.excluded_nodes = {list of IP addresses} The first parameter turns on the valid node checking feature. The latter two parameters respectively specify the IP addresses that are permitted to make network connections or denied from making network connections to the Oracle server processes. A combination of the parameters listed above can effectively prevent the Oracle database server from consuming Windows NT memory in the manner described. ISS Database Scanner scans Oracle, Microsoft SQL Server, and Sybase Adaptive Server for potential security vulnerabilities and provides the ability to assess and reduce misconfigurations in Oracle installations. ISS Consulting also provides a variety of database security offerings, including development of security policy, security assessments, and penetration testing. Credits: This vulnerability was researched by Jon Isaac of Internet Security Systems. ISS would like to thank Oracle for their response and handling of this vulnerability. Additional Information: The Common Vulnerabilities and Exposures (CVE) project has assigned the name CAN-2001-0513 to this issue. This is a candidate for inclusion in the CVE list <http://cve.mitre.org>, which standardizes names for security problems. ______ About Internet Security Systems (ISS) Internet Security Systems is the leading global provider of security management solutions for the Internet, protecting digital assets and ensuring safe and uninterrupted e-business. With its industry-leading intrusion detection and vulnerability assessment, remote managed security services, and strategic consulting and education offerings, ISS is a trusted security provider to more than 8,000 customers worldwide including 21 of the 25 largest U.S. commercial banks and the top 10 U.S. telecommunications companies. Founded in 1994, ISS is headquartered in Atlanta, GA, with additional offices throughout North America and international operations in Asia, Australia, Europe, Latin America and the Middle East. For more information, visit the Internet Security Systems web site at www.iss.net or call 888-901-7477. Copyright (c) 2001 Internet Security Systems, Inc. Permission is hereby granted for the redistribution of this Alert electronically. It is not to be edited in any way without express consent of the X-Force. If you wish to reprint the whole or any part of this Alert in any other medium excluding electronic medium, please e-mail xforce@iss.net for permission. Disclaimer The information within this paper may change without notice. Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties with regard to this information. In no event shall the author be liable for any damages whatsoever arising out of or in connection with the use or spread of this information. Any use of this information is at the user's own risk. X-Force PGP Key available at: http://xforce.iss.net/sensitive.php as well as on MIT's PGP key server and PGP.com's key server. Please send suggestions, updates, and comments to: X-Force xforce@iss.net of Internet Security Systems, Inc. - -----BEGIN PGP SIGNATURE----- Version: 2.6.3a Charset: noconv iQCVAwUBOy/R9TRfJiV99eG9AQEdkwQAhJ59O40mTcpye8TvYL/CJ2fRm5H3fNOy jn146dQxYWMJAiB+3Dky2Rc/M83yu60hA+oey5EZ39blEzEGupturZAHdDmv2LEv 8nMBQDy6T+MBJBzoS2TeKFWvfw4MhBjQcBkEW3qkH3GzKgMNkTeNMATlNoGJHDJC WeBv5sQdZHg= =0Ogi - -----END PGP SIGNATURE----- - --------------------------END INCLUDED TEXT-------------------- You have received this e-mail bulletin as a result of your organisation's registration with AusCERT. The mailing list you are subscribed to is maintained within your organisation, so if you do not wish to continue receiving these bulletins you should contact your local IT manager. If you do not know who that is, please send an email to auscert@auscert.org.au and we will forward your request to the appropriate person. This security bulletin is provided as a service to AusCERT's members. 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Previous advisories and external security bulletins can be retrieved from: http://www.auscert.org.au/Information/advisories.html If you believe that your system has been compromised, contact AusCERT or your representative in FIRST (Forum of Incident Response and Security Teams). Internet Email: auscert@auscert.org.au Facsimile: (07) 3365 7031 Telephone: (07) 3365 4417 (International: +61 7 3365 4417) AusCERT personnel answer during Queensland business hours which are GMT+10:00 (AEST). On call after hours for emergencies. -----BEGIN PGP SIGNATURE----- Version: 2.6.3i Charset: noconv Comment: ftp://ftp.auscert.org.au/pub/auscert/AUSCERT_PGP.key iQCVAwUBOzC6rCh9+71yA2DNAQF25wP9E0rKyoqh5fx4O+ZWJQgoXJbCGiFCb4Of Mnfd0fh0fs5bEhkHrULJcdxaI39J8W6NsYCYe0w26fxJwcpwOYVkQWLvDYmFEZdZ asXTpzCc9YgQWruodgKaGjcW/EC/lFERTh39o3lnYUvhXLupEJd/A8gH+ucKS2xb za89OHZPSWI= =LeGZ -----END PGP SIGNATURE-----