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-----BEGIN PGP SIGNED MESSAGE----- =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2003.0446 -- RHSA-2003:173-01 Updated ypserv packages fix a denial of service vulnerability 27 June 2003 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: ypserv Publisher: Red Hat Operating System: Red Hat Linux 9.0 Red Hat Linux 8.0 Red Hat Linux 7.x Platform: i386 IA-64 Impact: Denial of Service Access Required: Remote CVE Names: CAN-2003-0251 - --------------------------BEGIN INCLUDED TEXT-------------------- - -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 - - --------------------------------------------------------------------- Red Hat Security Advisory Synopsis: Updated ypserv packages fix a denial of service vulnerability Advisory ID: RHSA-2003:173-01 Issue date: 2003-06-25 Updated on: 2003-06-25 Product: Red Hat Linux Keywords: NIS ypserver DOS Cross references: Obsoletes: CVE Names: CAN-2003-0251 - - --------------------------------------------------------------------- 1. Topic: Updated ypserv packages fixing a denial of service vulnerability are now available. 2. Relevant releases/architectures: Red Hat Linux 7.1 - i386 Red Hat Linux 7.2 - i386, ia64 Red Hat Linux 7.3 - i386 Red Hat Linux 8.0 - i386 Red Hat Linux 9 - i386 3. Problem description: The ypserv package contains the Network Information Service (NIS) server. A vulnerability has been discovered in the ypserv NIS server prior to version 2.7. If a malicious client queries ypserv via TCP and subsequently ignores the server's response, ypserv will block attempting to send the reply. This results in ypserv failing to respond to other client requests. Versions 2.7 and above of ypserv have been altered to fork a child for each client request, thus preventing any one request from causing the server to block. Red Hat recommends that users of NIS upgrade to these packages, which contain version 2.8.0 of ypserv and are therefore not vulnerable to this issue. 4. Solution: Before applying this update, make sure all previously released errata relevant to your system have been applied. To update all RPMs for your particular architecture, run: rpm -Fvh [filenames] where [filenames] is a list of the RPMs you wish to upgrade. Only those RPMs which are currently installed will be updated. Those RPMs which are not installed but included in the list will not be updated. Note that you can also use wildcards (*.rpm) if your current directory *only* contains the desired RPMs. Please note that this update is also available via Red Hat Network. Many people find this an easier way to apply updates. To use Red Hat Network, launch the Red Hat Update Agent with the following command: up2date This will start an interactive process that will result in the appropriate RPMs being upgraded on your system. 5. RPMs required: Red Hat Linux 7.1: SRPMS: ftp://updates.redhat.com/7.1/en/os/SRPMS/ypserv-2.8-0.72E.src.rpm i386: ftp://updates.redhat.com/7.1/en/os/i386/ypserv-2.8-0.72E.i386.rpm Red Hat Linux 7.2: SRPMS: ftp://updates.redhat.com/7.2/en/os/SRPMS/ypserv-2.8-0.72E.src.rpm i386: ftp://updates.redhat.com/7.2/en/os/i386/ypserv-2.8-0.72E.i386.rpm ia64: ftp://updates.redhat.com/7.2/en/os/ia64/ypserv-2.8-0.72E.ia64.rpm Red Hat Linux 7.3: SRPMS: ftp://updates.redhat.com/7.3/en/os/SRPMS/ypserv-2.8-0.73E.src.rpm i386: ftp://updates.redhat.com/7.3/en/os/i386/ypserv-2.8-0.73E.i386.rpm Red Hat Linux 8.0: SRPMS: ftp://updates.redhat.com/8.0/en/os/SRPMS/ypserv-2.8-0.80E.src.rpm i386: ftp://updates.redhat.com/8.0/en/os/i386/ypserv-2.8-0.80E.i386.rpm Red Hat Linux 9: SRPMS: ftp://updates.redhat.com/9/en/os/SRPMS/ypserv-2.8-0.9E.src.rpm i386: ftp://updates.redhat.com/9/en/os/i386/ypserv-2.8-0.9E.i386.rpm 6. Verification: MD5 sum Package Name - - -------------------------------------------------------------------------- db17bee9fdb6d553dbb57850abff456a 7.1/en/os/SRPMS/ypserv-2.8-0.72E.src.rpm a51f5a9adf6ff4f255678e7407982a7e 7.1/en/os/i386/ypserv-2.8-0.72E.i386.rpm db17bee9fdb6d553dbb57850abff456a 7.2/en/os/SRPMS/ypserv-2.8-0.72E.src.rpm a51f5a9adf6ff4f255678e7407982a7e 7.2/en/os/i386/ypserv-2.8-0.72E.i386.rpm c300d319d7e883d5197b63f2e23fec88 7.2/en/os/ia64/ypserv-2.8-0.72E.ia64.rpm c1977878cc0c0f90a9d55a4ae3b3bfe3 7.3/en/os/SRPMS/ypserv-2.8-0.73E.src.rpm 4af8d607cf8ba600288b5a5f164bf2f6 7.3/en/os/i386/ypserv-2.8-0.73E.i386.rpm a606ee4aedc08cf7065e39d79b5e7474 8.0/en/os/SRPMS/ypserv-2.8-0.80E.src.rpm 9b72853f34de52966ff929218d1948bf 8.0/en/os/i386/ypserv-2.8-0.80E.i386.rpm 158b6b1ea17e996f2909ed98e444d683 9/en/os/SRPMS/ypserv-2.8-0.9E.src.rpm 86be6a349c1770893c6965611e29dc70 9/en/os/i386/ypserv-2.8-0.9E.i386.rpm These packages are GPG signed by Red Hat for security. Our key is available from http://www.redhat.com/security/keys.html You can verify each package with the following command: rpm --checksig -v <filename> If you only wish to verify that each package has not been corrupted or tampered with, examine only the md5sum with the following command: md5sum <filename> 7. References: http://www.linux-nis.org/nis/ypserv/ChangeLog http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2003-0251 8. Contact: The Red Hat security contact is <secalert@redhat.com>. More contact details at http://www.redhat.com/solutions/security/news/contact.html Copyright 2003 Red Hat, Inc. - -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.0.7 (GNU/Linux) iD8DBQE++ZagXlSAg2UNWIIRAj73AKCy2mfA4hQMYMcwWhayXK6OXa41YACfbcTT UZwwNvAZjb2riLlj8VbBsLk= =u6xU - -----END PGP SIGNATURE----- - --------------------------END INCLUDED TEXT-------------------- You have received this e-mail bulletin as a result of your organisation's registration with AusCERT. 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It may not be updated when updates to the original are made. If downloading at a later date, it is recommended that the bulletin is retrieved directly from the author's website to ensure that the information is still current. Contact information for the authors of the original document is included in the Security Bulletin above. If you have any questions or need further information, please contact them directly. 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 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 iQCVAwUBPvu18Ch9+71yA2DNAQGI4wQAkKO7bYyZzEq6Wb6NmM+7300ZOBkhcPua p8ayVgiHrlSX1v/fV6fINqCu7Lwt67+t002zfXVMBIhMnIMpZ59cHDNhX7ZTwnsS PX+SRbSk6oqE6lyF0Z9ba1Y4KGmWzBbwIvufrLE/Y1azV2dfuvyaw6t8JnKwED0A RpYhFvm/4gs= =Zxnh -----END PGP SIGNATURE-----