From secure@hpchs.cup.hp.com Tue Jul 19 13:55:31 2005 From: Security Alert To: bugtraq@securityfocus.com Date: Tue, 19 Jul 2005 04:36:18 -0700 Subject: HPSBUX01164 SSRT4884 rev.4 - HP-UX TCP/IP Remote Denial of Service (DoS) -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 HP SECURITY BULLETIN HPSBUX01164 REVISION: 4 SSRT4884 rev.4 - HP-UX TCP/IP Remote Denial of Service (DoS) NOTICE: There are no restrictions for distribution of this Security Bulletin provided that it remains complete and intact. The information in this Security Bulletin should be acted upon as soon as possible. INITIAL RELEASE: 10 July 2005 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: AFFECTED VERSIONS HP-UX B.11.22 HP-UX B.11.00 ============= Networking.NET2-KRN action: set ip_pmtu_strategy= 0 and either install binary files or filter ICMP HP-UX B.11.11 ============= Networking.NET2-KRN action: set ip_pmtu_strategy= 0 and install PHNE_33159 HP-UX B.11.23 ============= Networking.NET2-KRN ->action: set ip_pmtu_strategy= 0 and install PHNE_32606 HP-UX B.11.11 HP-UX B.11.23 ============= TOUR_PRODUCT.T-NET2-KRN action: set ip_pmtu_strategy= 0 and filter ICMP HP-UX B.11.04 ============= Networking.NET2-KRN action: set ip_pmtu_strategy= 0 and filter ICMP END AFFECTED VERSIONS Note: The latest TOUR (Transport Optional Upgrade Release), version 2.4, is available on B.11.11 only. The latest Transport Functionality is available to B.11.23 customers in the HP-UX 11i v2 September 2004 release. Customers using TOUR on B.11.23 can apply the workaround (set ip_pmtu_strategy= 0 and filter ICMP) or upgrade to the HP-UX 11i v2 September 2004 release. After upgrading the action for B.11.23 Networking.NET2-KRN listed above should be implemented. RESOLUTION: As reported in NISCC VU#532967 ICMP messages may be used to attack TCP/IP connections. There are three issues reported in NISCC VU#532967: CVE number: CAN-2004-0790 CVE number: CAN-2004-0791 CVE number: CAN-2004-1060 Workarounds are available for all three of these issues. Until binary files are available for B.11.04 the workarounds should be used. ->Binary files are available for CAN-2004-0790 and CAN-2004-0791 for HP-UX B.11.00 and B.11.22. Since PHNE_33159 is now available for B.11.11 the preliminary binary files for B.11.11 have been removed from the ftp site. ->Since PHNE_32606 is now available for B.11.23 the preliminary binary files for B.11.23 have been removed from the ftp site. Note: If the TOUR (Transport Optional Upgrade Release) product is installed the binary files cannot be used. Until the TOUR product is revised there are several options: B.11.11 1. Use the workarounds. or 2. Remove TOUR and install the binary files. B.11.23 1. Use the workarounds. or 2. Upgrade to the HP-UX 11i v2 September 2004 release and install the binary files. TOUR(Transport Optional Upgrade Release) is available from . Workaround for CAN-2004-1060 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 has been implemented. Customers should consider whether this check reduces the risk of the exploit to the point that setting ip_pmtu_strategy=0 is not required. If the workaround for CAN-2004-1060 is to be used, please note the following: ================================================= HPSBUX01137 recommends setting ip_pmtu_strategy = 0 or 3 as a workaround for the problem of CAN-2005-1192. CAN-2004-1060 has a different root cause and cannot be worked around with p_pmtu_strategy=3. To work around both CAN-2005-1192 and CAN-2004-1060 ip_pmtu_strategy=0 must be used. Please refer to the Manual Actions section below for a summary of the required actions. Workarounds: CAN-2004-0790 and CAN-2004-0791 Filter out the following ICMP messages: Type 3, Code 2 (Destination Unreachable, Protocol Unreachable) Type 3, Code 3 (Destination Unreachable, Port Unreachable) Type 4, Code 0 (Source Quench) CAN-2004-1060 Set ip_pmtu_strategy=0. Note: Filtering "Protocol Unreachable" and "Port Unreachable" should not be done without careful testing. Filtering these out may interfere with the correct functioning of network components. Filtering "Source Quench" should present little risk. Setting 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 Preliminary binary files ============== ->Preliminary binary files are available for B.11.00 and B.11.22. Patches are available for B.11.11 and B.11.23. The patches and the preliminary binary files address CAN-2004-0790 and CAN-2004-0791 only. Although changes in the patches and binary files 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. Instructions for downloading and installing the binary files are contained in readme files available here: System: hprc.external.hp.com (192.170.19.51) Login: icmp Password: icmp FTP Access: ftp://icmp:icmp@hprc.external.hp.com/ or: ftp://icmp:icmp@192.170.19.51/ Note: The links above may not work for all browsers. If the link fails the url should be entered directly into the browser's address field. Since a patch is available for B.11.11 the readme.11.11.txt and corresponding binary files have been removed from the ftp site. ->Since a patch is available for B.11.23 the readme.11.23.txt and corresponding binary files have been removed from the ftp site. Download the appropriate readme file containing further instructions: readme.11.00.txt readme.11.22.txt Verify the cksum or md5sum: ->Note: The readme files have not changed since rev.1 of this Security Bulletin. cksum readme* 2844254744 2546 readme.11.00.txt 2836317466 2469 readme.11.22.txt md5sum readme* d28504f8532192de6a4f33bba4ea90ec readme.11.00.txt cafbb24f3dc7131501142f75deaeccbd readme.11.22.txt Download and install the binary files as discussed in the readme files. The binary files are available in the same directory as the readme files. For B.11.11 download and install PHNE_33159. The patch is available from < http://itrc.hp.com>. ->For B.11.23 download and install PHNE_32606. The patch is available from < http://itrc.hp.com>. MANUAL ACTIONS: Yes - NonUpdate 1. Set ip_pmtu_strategy=0 2. EITHER a. Filter out the following ICMP messages: Type 3, Code 2 (Destination Unreachable, Protocol Unreachable) Type 3, Code 3 (Destination Unreachable, Port Unreachable) Type 4, Code 0 (Source Quench) OR b. Install the appropriate binary file or patch (binary file not available for B.11.04). BULLETIN REVISION HISTORY: Revision 0: 25 May 2005 Initial release Revision 1: 1 June 2005 Binary files for B.11.00 and B.11.22 are available. Added information about CAN-2004-1060. The "set ip_pmtu_strategy=0" workaround is required even if binary files are installed. Removed IPSec information. Revision 2: 19 June 2005 TOUR (Transport Optional Upgrade Release) on B.11.11 and B.11.23 is potentially vulnerable. Added a description of the sequence number check implemented in the binary files. Revision 3: 27 June 2005 PHNE_33159 is available for B.11.11. The B.11.11 binary files have been removed from the ftp site. Revision 4: 10 July 2005 PHNE_32606 is available for B.11.23. The B.11.23 binary files have been removed from the ftp site. HP-UX SPECIFIC SECURITY BULLETINS*: 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://www.software.hp.com/cgi-bin/swdepot_parser.cgi/cgi/ displayProductInfo.pl?productNumber=B6834AA 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@hp.com. It is strongly recommended that security related information being communicated to HP be encrypted using PGP, especially exploit information. To obtain the security-alert PGP key please send an e-mail message to security-alert@hp.com with the Subject of 'get key' (no quotes). 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To review previously published Security Bulletins visit: http://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: 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/AwUBQtJVE+AfOvwtKn1ZEQKwPwCeLKNxE1048xGZniru4epJ6YAqYIcAn2+Y fjKXZ3hbnTeQeIn9Kk9ePC1d =cFE+ -----END PGP SIGNATURE-----