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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2007.0533 -- [Win][UNIX/Linux][Solaris][AIX][OSX] IBM Tivoli Provisioning Manager for OS Deployment TFTP Blocksize DoS Vulnerability 18 July 2007 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: IBM Tivoli Provisioning Manager Publisher: iDefense Operating System: UNIX variants (UNIX, Linux, OSX) Windows AIX Impact: Denial of Service Access: Remote/Unauthenticated CVE Names: CVE-2007-3268 Original Bulletin: http://www-1.ibm.com/support/docview.wss?uid=swg24016347 http://labs.idefense.com/intelligence/vulnerabilities/display.php?id=560 - --------------------------BEGIN INCLUDED TEXT-------------------- IBM Tivoli Provisioning Manager for OS Deployment TFTP Blocksize DoS Vulnerability iDefense Security Advisory 07.17.07 http://labs.idefense.com/intelligence/vulnerabilities/ Jul 17, 2007 I. BACKGROUND IBM Corp.'s Tivoli Provisioning Manager for OS Deployment is a network boot server that facilitates central management of networked workstations. It implements Preboot Execution Environment (PXE), a Web-based administration service, DHCP, TFTP, and several additional protocols. More information can be found at the following URL. http://www-306.ibm.com/software/tivoli/products/prov-mgr-os-deploy/ II. DESCRIPTION Remote exploitation of a denial of service vulnerability within version 5.1.0.2 of IBM Corp.'s Tivoli Provisioning Manager for OS Deployment allows attackers to deny service to all product functionality. This vulnerability specifically exists in the TFTP protocol implementation. When processing a read request (RRQ), an integer division by zero error can be triggered by supplying an invalid "blksize" argument. This exception is not handled and will result in the rembo.exe service terminating. III. ANALYSIS Exploitation allows an attacker to cause the service to terminate unexpectedly due to an exception that occurs when dividing by zero. No authentication is required to access the vulnerable code. The attacker need only be able to send a specially crafted request to the TFTP port (UDP port 69) of the vulnerable machine. This will deny service to all functionality provided by this service. This includes DHCP, TFTP, PXE, HTTP, HTTPS, as well as several other services. IV. DETECTION iDefense has confirmed the existence of this vulnerability in version 5.1.0.2 of IBM Corp.'s Tivoli Provisioning Manager for OS Deployment. Version 5.1.0.116 was tested and found not to be vulnerable. V. WORKAROUND Employing firewalls to limit access to the affected service will mitigate exposure to this vulnerability. VI. VENDOR RESPONSE The IBM Tivoli team has addressed this vulnerability within Tivoli Provisioning Manager for OS Deployment 5.1 Fix Pack 3. More information is available from IBM Document swg24016347 at the following URL. http://www-1.ibm.com/support/docview.wss?uid=swg24016347 VII. CVE INFORMATION The Common Vulnerabilities and Exposures (CVE) project has assigned the name CVE-2007-3268 to this issue. This is a candidate for inclusion in the CVE list (http://cve.mitre.org/), which standardizes names for security problems. VIII. DISCLOSURE TIMELINE 06/19/2007 Initial vendor notification 06/19/2007 Initial vendor response 07/17/2007 Coordinated public disclosure IX. CREDIT This vulnerability was reported to iDefense by Manuel Santamarina Suarez. Get paid for vulnerability research http://labs.idefense.com/methodology/vulnerability/vcp.php Free tools, research and upcoming events http://labs.idefense.com/ X. LEGAL NOTICES Copyright © 2007 iDefense, Inc. Permission is granted for the redistribution of this alert electronically. It may not be edited in any way without the express written consent of iDefense. If you wish to reprint the whole or any part of this alert in any other medium other than electronically, please e-mail customerservice@idefense.com for permission. Disclaimer: The information in the advisory is believed to be accurate at the time of publishing based on currently available information. Use of the information constitutes acceptance for use in an AS IS condition. There are no warranties with regard to this information. Neither the author nor the publisher accepts any liability for any direct, indirect, or consequential loss or damage arising from use of, or reliance on, this information. - --------------------------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. 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Previous advisories and external security bulletins can be retrieved from: http://www.auscert.org.au/render.html?cid=1980 If you believe that your computer system has been compromised or attacked in any way, we encourage you to let us know by completing the secure National IT Incident Reporting Form at: http://www.auscert.org.au/render.html?it=3192 =========================================================================== Australian Computer Emergency Response Team The University of Queensland Brisbane Qld 4072 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 member emergencies only. =========================================================================== -----BEGIN PGP SIGNATURE----- Comment: http://www.auscert.org.au/render.html?it=1967 iQCVAwUBRp1OdCh9+71yA2DNAQIq9wP+JG3wPlPtzkUP0KZIodxs9cfTycRDjBGp KG6FstVrgTHx1L2Ue9Rmt72YMz9BiQoLQYBYxcSbXYyi3/l1CqRUcHnvvRwjRZ+d xFyGzIIYIaxqxDXctA9EkZerFM6FeJC45GspFhfVmTMwEMd2AyTu6zoWnj5xgRMu 16wTIJ/XfRI= =D5xD -----END PGP SIGNATURE-----