Published:
11 November 1999
Protect yourself against future threats.
-----BEGIN PGP SIGNED MESSAGE----- =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-1999.172 -- RHSA-1999:053-01 new NFS server packages available (5.2, 4.2) 12 November 1999 =========================================================================== Red Hat Inc. has released the following advisory concerning a buffer overflow vulnerability in the user space NFS daemon that ships with Red Hat Linux 4.2 and 5.2. This vulnerability may be exploited to allow users to execute arbitrary code as the owner of the NFS daemon if they have read/write access to a share on the affected server. This may allow remote users to gain root access. - --------------------------BEGIN INCLUDED TEXT-------------------- - --------------------------------------------------------------------- Red Hat, Inc. Security Advisory Synopsis: new NFS server packages available (5.2, 4.2) Advisory ID: RHSA-1999:053-01 Issue date: 1999-11-11 Updated on: 1999-11-11 Keywords: nfs-server PATH_MAX NAME_MAX rpc.nfsd Cross references: Bugtraq id #782 - --------------------------------------------------------------------- 1. Topic: A buffer overflow exists in the user space NFS daemon that shipped with Red Hat Linux 4.2 and 5.2. 2. Relevant releases/architectures: Red Hat Linux 4.x, all platforms Red Hat Linux 5.x, all platforms Red Hat Linux 6.x uses the knfsd kernel space NFS daemon, and is not affected by this problem. 3. Problem description: The length of a path name was not checked on the removal of a directory. If a long enough directory name was created, the buffer holding the pathname would overflow, and the possibility exists that arbitrary code could be executed as the user the NFS server runs as (root). Exploiting this buffer overflow does require read/write access to a share on an affected server. 4. Solution: It is recommended that all users of Red Hat Linux 4.x and 5.x update to the fixed packages. Thanks go to Olaf Kirch (okir@monad.swb.de) for providing a fix. For each RPM for your particular architecture, run: rpm -Uvh <filename> where filename is the name of the RPM. 5. Bug IDs fixed (http://developer.redhat.com/bugzilla for more info): 6. Obsoleted by: 7. Conflicts with: 8. RPMs required: Red Hat Linux 4.x: Intel: ftp://updates.redhat.com/4.2/i386/nfs-server-2.2beta47-0.i386.rpm ftp://updates.redhat.com/4.2/i386/nfs-server-clients-2.2beta47-0.i386.rpm Alpha: ftp://updates.redhat.com/4.2/alpha/nfs-server-2.2beta47-0.alpha.rpm ftp://updates.redhat.com/4.2/alpha/nfs-server-clients-2.2beta47-0.alpha.rpm Sparc: ftp://updates.redhat.com/4.2/sparc/nfs-server-2.2beta47-0.sparc.rpm ftp://updates.redhat.com/4.2/sparc/nfs-server-clients-2.2beta47-0.sparc.rpm Source packages: ftp://updates.redhat.com/4.2/SRPMS/nfs-server-2.2beta47-0.src.rpm Red Hat Linux 5.x: Intel: ftp://updates.redhat.com/5.2/i386/nfs-server-2.2beta47-1.i386.rpm ftp://updates.redhat.com/5.2/i386/nfs-server-clients-2.2beta47-1.i386.rpm Alpha: ftp://updates.redhat.com/5.2/alpha/nfs-server-2.2beta47-1.alpha.rpm ftp://updates.redhat.com/5.2/alpha/nfs-server-clients-2.2beta47-1.alpha.rpm Sparc: ftp://updates.redhat.com/5.2/sparc/nfs-server-2.2beta47-1.sparc.rpm ftp://updates.redhat.com/5.2/sparc/nfs-server-clients-2.2beta47-1.sparc.rpm Source packages: ftp://updates.redhat.com/5.2/SRPMS/nfs-server-2.2beta47-1.src.rpm 9. Verification: MD5 sum Package Name - -------------------------------------------------------------------------- 09b6c7ff370f58140aac7d1a41b50035 i386/nfs-server-2.2beta47-0.i386.rpm 14e1e5e5bcba01f9bb9cb6dfe9e2627e i386/nfs-server-clients-2.2beta47-0.i386.rpm 9ce6b7afd8ef5a1d5b481ee9fe2530d3 alpha/nfs-server-2.2beta47-0.alpha.rpm 6306ba518cd64b0d018b8b2786ecb128 alpha/nfs-server-clients-2.2beta47-0.alpha.rpm cf15f95dd9b13844b63a9e7607a873ee sparc/nfs-server-2.2beta47-0.sparc.rpm a450ee5b850fb6ed906b3527a2165ec5 sparc/nfs-server-clients-2.2beta47-0.sparc.rpm e6ffef85c75620ebebf0c3244a181c46 SRPMS/nfs-server-2.2beta47-0.src.rpm 1d408903070fa5313072fe8886917bda i386/nfs-server-2.2beta47-1.i386.rpm e4c30ae30f3cbdd4ff2cd90232c46e0e i386/nfs-server-clients-2.2beta47-1.i386.rpm 1d6f0a6c28b4cb20e1f203bb8d376af1 alpha/nfs-server-2.2beta47-1.alpha.rpm 75f89bcd51df6771d993aaee6f812ce7 alpha/nfs-server-clients-2.2beta47-1.alpha.rpm 0dc37d253e7620ce300ef51b15af562b sparc/nfs-server-2.2beta47-1.sparc.rpm 21c743b1631db675dd1aac7007c9a37a sparc/nfs-server-clients-2.2beta47-1.sparc.rpm 810ca1bd9d362031ed21c664eb2024ac SRPMS/nfs-server-2.2beta47-1.src.rpm These packages are GPG signed by Red Hat, Inc. for security. Our key is available at: http://www.redhat.com/corp/contact.html You can verify each package with the following command: rpm --checksig <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: rpm --checksig --nogpg <filename> 10. References: - --------------------------END INCLUDED TEXT-------------------- This security bulletin is provided as a service to AusCERT's members. As AusCERT did not write the document quoted above, AusCERT has had no control over its content. The decision to use any or all of this information is the responsibility of each user or organisation, and should be done so in accordance with site policies and procedures. NOTE: This is only the original release of the security bulletin. 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 original authors 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/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). 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