[Full-Disclosure] [RHSA-2003:041-12] Updated VNC packages fix replay and cookie vulnerabilities From: bugzilla@redhat.com To: redhat-watch-list@redhat.com, redhat-announce-list@redhat.com CC: bugtraq@securityfocus.com, full-disclosure@lists.netsys.com Date: Today 09.40.00 --------------------------------------------------------------------- Red Hat, Inc. Red Hat Security Advisory Synopsis: Updated VNC packages fix replay and cookie vulnerabilities Advisory ID: RHSA-2003:041-12 Issue date: 2003-02-07 Updated on: 2003-02-20 Product: Red Hat Linux Keywords: vnc challenge replay cookie mkcookie Cross references: Obsoletes: CVE Names: CAN-2002-1336 CAN-2002-1511 --------------------------------------------------------------------- 1. Topic: Updated VNC packages are available to fix a challenge replay vulnerability and a weak cookie vulnerability. 2. Relevant releases/architectures: Red Hat Linux 7.0 - i386 Red Hat Linux 7.1 - i386 Red Hat Linux 7.2 - i386 Red Hat Linux 7.3 - i386 Red Hat Linux 8.0 - i386 3. Problem description: VNC is a tool for providing a remote graphical user interface. Two vulnerabilities have been found in versions of VNC shipped by Red Hat. The VNC server acts as an X server, but the script for starting it generates an MIT X cookie (which is used for X authentication) without using a strong enough random number generator. This could allow an attacker to be able to more easily guess the authentication cookie. The VNC DES authentication scheme is implemented using a challenge-response architecture, producing a random and different challenge for each authentication attempt. A bug in the function for generating the random challenge caused the random seed to get reset to the current time on every authentication attempt. Therefore, two authentication attempts within the same second could receive the same challenge. An eavesdropper could exploit this vulnerability by replaying the response, thereby gaining authentication. All users of VNC are advised to upgrade to these erratum packages, which contain patches to correct these issues. Note that when using VNC on an untrusted network, always make sure to tunnel it through a secure authenticated protocol such as SSH. 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. Bug IDs fixed (http://bugzilla.redhat.com/bugzilla for more info): 78828 - Upgrade to tightVNC 1.2.7 from 1.2.2 6. RPMs required: Red Hat Linux 7.0: SRPMS: ftp://updates.redhat.com/7.0/en/os/SRPMS/vnc-3.3.3r2-18.6.src.rpm i386: ftp://updates.redhat.com/7.0/en/os/i386/vnc-3.3.3r2-18.6.i386.rpm ftp://updates.redhat.com/7.0/en/os/i386/vnc-server-3.3.3r2-18.6.i386.rpm ftp://updates.redhat.com/7.0/en/os/i386/vnc-doc-3.3.3r2-18.6.i386.rpm Red Hat Linux 7.1: SRPMS: ftp://updates.redhat.com/7.1/en/os/SRPMS/vnc-3.3.3r2-18.6.src.rpm i386: ftp://updates.redhat.com/7.1/en/os/i386/vnc-3.3.3r2-18.6.i386.rpm ftp://updates.redhat.com/7.1/en/os/i386/vnc-server-3.3.3r2-18.6.i386.rpm ftp://updates.redhat.com/7.1/en/os/i386/vnc-doc-3.3.3r2-18.6.i386.rpm Red Hat Linux 7.2: SRPMS: ftp://updates.redhat.com/7.2/en/os/SRPMS/vnc-3.3.3r2-18.6.src.rpm i386: ftp://updates.redhat.com/7.2/en/os/i386/vnc-3.3.3r2-18.6.i386.rpm ftp://updates.redhat.com/7.2/en/os/i386/vnc-server-3.3.3r2-18.6.i386.rpm ftp://updates.redhat.com/7.2/en/os/i386/vnc-doc-3.3.3r2-18.6.i386.rpm Red Hat Linux 7.3: SRPMS: ftp://updates.redhat.com/7.3/en/os/SRPMS/vnc-3.3.3r2-28.2.src.rpm i386: ftp://updates.redhat.com/7.3/en/os/i386/vnc-3.3.3r2-28.2.i386.rpm ftp://updates.redhat.com/7.3/en/os/i386/vnc-server-3.3.3r2-28.2.i386.rpm ftp://updates.redhat.com/7.3/en/os/i386/vnc-doc-3.3.3r2-28.2.i386.rpm Red Hat Linux 8.0: SRPMS: ftp://updates.redhat.com/8.0/en/os/SRPMS/vnc-3.3.3r2-39.2.src.rpm i386: ftp://updates.redhat.com/8.0/en/os/i386/vnc-3.3.3r2-39.2.i386.rpm ftp://updates.redhat.com/8.0/en/os/i386/vnc-server-3.3.3r2-39.2.i386.rpm ftp://updates.redhat.com/8.0/en/os/i386/vnc-doc-3.3.3r2-39.2.i386.rpm 7. Verification: MD5 sum Package Name -------------------------------------------------------------------------- 9238c1864c7571432c232b35d4047cbd 7.0/en/os/SRPMS/vnc-3.3.3r2-18.6.src.rpm c159b4fa8ac650a799e64acbebb3934e 7.0/en/os/i386/vnc-3.3.3r2-18.6.i386.rpm 7087a97e858bd5d38bccb4e69ce2ebdc 7.0/en/os/i386/vnc-doc-3.3.3r2-18.6.i386.rpm 678cbceba744439bca85bb3d01279e59 7.0/en/os/i386/vnc-server-3.3.3r2-18.6.i386.rpm 9238c1864c7571432c232b35d4047cbd 7.1/en/os/SRPMS/vnc-3.3.3r2-18.6.src.rpm c159b4fa8ac650a799e64acbebb3934e 7.1/en/os/i386/vnc-3.3.3r2-18.6.i386.rpm 7087a97e858bd5d38bccb4e69ce2ebdc 7.1/en/os/i386/vnc-doc-3.3.3r2-18.6.i386.rpm 678cbceba744439bca85bb3d01279e59 7.1/en/os/i386/vnc-server-3.3.3r2-18.6.i386.rpm 9238c1864c7571432c232b35d4047cbd 7.2/en/os/SRPMS/vnc-3.3.3r2-18.6.src.rpm c159b4fa8ac650a799e64acbebb3934e 7.2/en/os/i386/vnc-3.3.3r2-18.6.i386.rpm 7087a97e858bd5d38bccb4e69ce2ebdc 7.2/en/os/i386/vnc-doc-3.3.3r2-18.6.i386.rpm 678cbceba744439bca85bb3d01279e59 7.2/en/os/i386/vnc-server-3.3.3r2-18.6.i386.rpm 10bbe07038a2a122affc6c5583b83c11 7.3/en/os/SRPMS/vnc-3.3.3r2-28.2.src.rpm 535f8e6e8b531efafc3906a09a7be81e 7.3/en/os/i386/vnc-3.3.3r2-28.2.i386.rpm cdb33d3b5367de1afe34d3b758096aa9 7.3/en/os/i386/vnc-doc-3.3.3r2-28.2.i386.rpm 40bc575df1a4360d14e0624013e89ecf 7.3/en/os/i386/vnc-server-3.3.3r2-28.2.i386.rpm 7cf3f738c2277cdcece3076c8c629e6e 8.0/en/os/SRPMS/vnc-3.3.3r2-39.2.src.rpm 6b20a3a761015ca503128cea711605a4 8.0/en/os/i386/vnc-3.3.3r2-39.2.i386.rpm db2ca9e3207bb536c80f3cc360f594c6 8.0/en/os/i386/vnc-doc-3.3.3r2-39.2.i386.rpm 900346576f15c15591e67f4284b4beb0 8.0/en/os/i386/vnc-server-3.3.3r2-39.2.i386.rpm These packages are GPG signed by Red Hat, Inc. for security. Our key is available at http://www.redhat.com/about/contact/pgpkey.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> 8. References: http://marc.theaimsgroup.com/?l=bugtraq&m=102753170201524 http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2002-1336 http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2002-1511 9. Contact: The Red Hat security contact is <security@redhat.com>. More contact details at http://www.redhat.com/solutions/security/news/contact.html Copyright 2003 Red Hat, Inc. _______________________________________________ Full-Disclosure - We believe in it. Charter: http://lists.netsys.com/full-disclosure-charter.html
glsa sent
