-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 SUPPORT COMMUNICATION - SECURITY BULLETIN Document ID: c00576017 Version: 8 HPSBUX01164 SSRT4884 HP-UX TCP/IP Remote Denial of Service (DoS) NOTICE: The information in this Security Bulletin should be acted upon as soon as possible. Release Date: 2005-05-25 Last Updated: 2005-12-06 Potential Security Impact: Remote Denial of Service (DoS) Source: Hewlett-Packard Company, HP Software Security Response Team VULNERABILITY SUMMARY A potential security vulnerability has been identified with HP-UX running TCP/IP. This vulnerability could be remotely exploited by an unauthorized user to cause a Denial of Service(DoS). References: NISCC VU#532967, CAN-2004-0790, CAN-2004-0791, CAN-2004-1060 SUPPORTED SOFTWARE VERSIONS*: ONLY impacted versions are listed. HP-UX B.11.00, B.11.04, B.11.11, B.11.22, B.11.23 running TCP/IP. HP-UX B.11.11 and B.11.23 running TOUR (Transport Optional Upgrade Release). BACKGROUND As reported in NISCC VU#532967: http://www.uniras.gov.uk/niscc/docs/al-20050412-00308.html?lang=en ICMP messages may be used to attack TCP/IP connections. There are three issues reported in NISCC VU#532967: CVE number: CAN-2004-0790 http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2004-0790 CVE number: CAN-2004-0791 http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2004-0791 CVE number: CAN-2004-1060 http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2004-1060 AFFECTED VERSIONS HP-UX B.11.00 ============= Networking.NET2-KRN action: install PHNE_33395, optionally set ip_pmtu_strategy=0 HP-UX B.11.04 ============= Networking.NET2-KRN action: install PHNE_33427, optionally set ip_pmtu_strategy=0 HP-UX B.11.11 ============= Networking.NET2-KRN action: install PHNE_33159, optionally set ip_pmtu_strategy=0 HP-UX B.11.22 ============= Networking.NET2-KRN action: install binary files, optionally set ip_pmtu_strategy=0 HP-UX B.11.23 ============= Networking.NET2-KRN action: install PHNE_32606, optionally set ip_pmtu_strategy=0 HP-UX B.11.11 HP-UX B.11.23 ============= TOUR_PRODUCT.T-NET2-KRN ->action: install revision A.03.00, optionally set ip_pmtu_strategy=0 END AFFECTED VERSIONS RESOLUTION HP has made the following patches, updates, and binary files available to resolve the issue. Patches are available for the core network product from http://itrc.hp.com : B.11.00 PHNE_33395 or subsequent B.11.04 PHNE_33427 or subsequent B.11.11 PHNE_33159 or subsequent B.11.23 PHNE_32606 or subsequent ->TOUR revision 3.0 is available from: ->http://www.hp.com/go/softwaredepot ->Binary files are available for B.11.22. Please write to ->security-alert@xxxxxx for more information. Optionally set ip_pmtu_strategy=0 to work around CAN-2004-1060. However, this may not be necessary: Although changes in the binary files and patches for CAN-2004-0790 and CAN-2004-0791 do not prevent the exploit of CAN-2004-1060, they do make it less likely to succeed. The sequence number check suggested in section 5.1 of 'ICMP attacks against TCP' has been implemented. The Internet Draft of 'ICMP attacks against TCP' can be found here: http://www.gont.com.ar/drafts/icmp-attacks-against-tcp.html Customers should consider whether this check reduces the risk of the exploit to the point that setting ip_pmtu_strategy=0 is not required. Note: ip_pmtu_strategy=0 sets the PMTU to 576 bytes and clears the "Don't Fragment" bit. This disables PMTU discovery. For IPv4 the Next-Hop MTU may be as low as 68 bytes. Therefore setting ip_pmtu_strategy=0 may cause performance to decrease. To set ip_pmtu_strategy=0: Edit /etc/rc.config.d/nddconf to add the following: TRANSPORT_NAME[n]=ip NDD_NAME[n]=ip_pmtu_strategy NDD_VALUE[n]=0 where 'n' is the next available index value as described in the nddconf comments. This value will take effect when the system is rebooted. Until the system can be rebooted use the following command to read the /etc/rc.config.d/nddconf file and set the tunable parameters: /usr/bin/ndd -c The ip_pmtu_strategy parameter can be displayed by the following command: /usr/bin/ndd -get /dev/ip ip_pmtu_strategy Note: Since open connections will remain potentially vulnerable until they are closed and certain internal data structures are released it is recommended that the system be rebooted. Note: There is a defect that will cause "ndd -c" to fail if there are more than 10 directives in /etc/rc.config.d/nddconf. That defect is fixed in the following patches: B.11.11 PHNE_25644 or subsequent B.11.04 PHNE_26076 or subsequent B.11.00 PHNE_26125 or subsequent MANUAL ACTIONS: Yes - NonUpdate Optionally set ip_pmtu_strategy=0 PRODUCT SPECIFIC INFORMATION HP-UX Security Patch Check: Security Patch Check revision B.02.00 analyzes all HP-issued Security Bulletins to provide a subset of recommended actions that potentially affect a specific HP-UX system. For more information: http://software.hp.com/portal/swdepot/displayProductInfo.do? productNumber=B6834AA UPDATE HISTORY Initial release: 25 May 2005 Update 1: 1 June 2005 Binary files for B.11.00 and B.11.22 are available. Update 2: 19 June 2005 Added TOUR information. Update 3: 27 June 2005 PHNE_33159 is available for B.11.11. Update 4: 10 July 2005 PHNE_32606 is available for B.11.23. Update 5: 24 July 2005 PHNE_33395 is available for B.11.00. Update 6: 15 August 2005 PHNE_33427 is available for B.11.04. Support: For further information, contact normal HP Services support channel. Report: To report a potential security vulnerability with any HP supported product, send Email to: security-alert@xxxxxxx It is strongly recommended that security related information being communicated to HP be encrypted using PGP, especially exploit information. To get the security-alert PGP key, please send an e-mail message as follows: To: security-alert@xxxxxx Subject: get key Subscribe: To initiate a subscription to receive future HP Security Bulletins via Email: http://h30046.www3.hp.com/driverAlertProfile.php?regioncode=NA& langcode=USENG&jumpid=in_SC-GEN__driverITRC&topiccode=ITRC On the web page: ITRC security bulletins and patch sign-up Under Step1: your ITRC security bulletins and patches - check ALL categories for which alerts are required and continue. Under Step2: your ITRC operating systems - verify your operating system selections are checked and save. To update an existing subscription: http://h30046.www3.hp.com/subSignIn.php Log in on the web page: Subscriber's choice for Business: sign-in. On the web page: Subscriber's Choice: your profile summary - use Edit Profile to update appropriate sections. To review previously published Security Bulletins visit: http://www.itrc.hp.com/service/cki/secBullArchive.do * The Software Product Category that this Security Bulletin relates to is represented by the 5th and 6th characters of the Bulletin number in the title: GN = HP General SW, MA = HP Management Agents, MI = Misc. 3rd party SW, MP = HP MPE/iX, NS = HP NonStop Servers, OV = HP OpenVMS, PI = HP Printing & Imaging, ST = HP Storage SW, TL = HP Trusted Linux, TU = HP Tru64 UNIX, UX = HP-UX, VV = HP Virtual Vault System management and security procedures must be reviewed frequently to maintain system integrity. HP is continually reviewing and enhancing the security features of software products to provide customers with current secure solutions. "HP is broadly distributing this Security Bulletin in order to bring to the attention of users of the affected HP products the important security information contained in this Bulletin. HP recommends that all users determine the applicability of this information to their individual situations and take appropriate action. HP does not warrant that this information is necessarily accurate or complete for all user situations and, consequently, HP will not be responsible for any damages resulting from user's use or disregard of the information provided in this Bulletin. To the extent permitted by law, HP disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose, title and non-infringement." (c)Copyright 2005 Hewlett-Packard Development Company, L.P. Hewlett-Packard Company shall not be liable for technical or editorial errors or omissions contained herein. The information provided is provided "as is" without warranty of any kind. To the extent permitted by law, neither HP nor its affiliates, subcontractors or suppliers will be liable for incidental, special or consequential damages including downtime cost; lost profits; damages relating to the procurement of substitute products or services; or damages for loss of data, or software restoration. The information in this document is subject to change without notice. Hewlett-Packard Company and the names of Hewlett-Packard products referenced herein are trademarks of Hewlett-Packard Company in the United States and other countries. Other product and company names mentioned herein may be trademarks of their respective owners. -----BEGIN PGP SIGNATURE----- Version: PGP 8.1 iQA/AwUBQ5bhOOAfOvwtKn1ZEQKzSgCg1iC5rsS3fg+NdLRiEgXs1RLFHtMAoI8f 7aOaCbh4wQ3lzcx/PDVZn5Cz =wJMN -----END PGP SIGNATURE-----