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-----BEGIN PGP SIGNED MESSAGE----- =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2000.104 -- Red Hat Security Advisory RHSA-2000:028-02 Netscape 4.73 available 25 May 2000 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: Netscape Navigator Netscape Communicator Vendor: Red Hat Operating System: Red Hat Linux 6.2 Red Hat Linux 5.2 Platform: x86, alpha Impact: Access Confidential Data Access Required: Remote Ref: ESB-2000.095 - --------------------------BEGIN INCLUDED TEXT-------------------- - --------------------------------------------------------------------- Red Hat, Inc. Security Advisory Synopsis: Netscape 4.73 available Advisory ID: RHSA-2000:028-02 Issue date: 2000-05-19 Updated on: 2000-05-19 Product: Red Hat Linux Keywords: netscape SSL telnet rlogin Cross references: http://www.securityfocus.com/vdb/bottom.html?section=discussion&vid=1188 - --------------------------------------------------------------------- 1. Topic: Netscape 4.73 packages are available. These new packages fix bugs in SSL certificate validation; these bugs could allow for the compromising of encrypted SSL sessions. It is recommended that all users of Netscape update to the new packages. 2. Relevant releases/architectures: Red Hat Linux 5.2 - i386 Red Hat Linux 6.2 - i386 alpha 3. Problem description: The description of the vulnerability, taken from http://www.securityfocus.com/: - -- An attacker poisons a nameserver to redirect all connections to www.goodguy.com, normally 100.100.100.100, to 99.99.99.99, www.badguy.com. The attacker causes all normal http requests to return what they normally would on www.goodguy.com, even though a user attempting to contact www.goodguy.com hits www.badguy.com. Upon getting a hit to www.badguy.com, the attacker causes an SSL connection to be established. This can be done by embedding a small image. The user may or may not get a warning about establishing a secure connection -- this warning is on by default, although many users will choose to disable this warning. The attacker needs to use a legitimate SSL key, certified by someone listed as trustworthy (thwate.com, for instance) The user can continue to shop to their hearts content, on the real site, as it's being proxied. When the user decides to check out, it will attempt to establish an SSL connection to www.goodguy.com. Upon checking the ip address for www.goodguy.com, for establishing an SSL connection, it will note that an SSL connection already exists to it's IP. The key, however, was issued to www.badguy.com. The SSL connection will be established, and by all indications appear to go to www.goodguy.com, when in fact it is to www.badguy.com. This could be used by a would be attacker to steal information such as credit cards, or any other information protected by SSL. - --- Another minor vulnerability exists in current versions of Netscape; by default, netscape will respond to rlogin: and telnet: URLs by launching a helper application of the appropriate type. It is possible that when following URLs of these types that certain information about the local user (user name, environment settings) can be exposed to a remote host. To change the default associations to avoid this, users can go to Edit->Preferences, and choose Communicator->Applications. Then, change the default commands associated with 'telnet' and 'rlogin' to something that does not open up a connection to the remote host, for example, simply 'xterm'. 4. Solution: For each RPM for your particular architecture, run: rpm -Fvh [filename] where filename is the name of the RPM. For Red Hat Linux 5.0 and 5.1, use the Red Hat Linux 5.2 packages. For Red Hat Linux 6.0 and 6.1, use the Red Hat Linux 6.2 packages. 5. Bug IDs fixed (http://bugzilla.redhat.com/bugzilla for more info): 11379 - Netscape 4.73 release for security problems in 4.72 6. RPMs required: Red Hat Linux 5.2: intel: ftp://ftp.redhat.com/5.2/i386/netscape-common-4.73-0.5.2.i386.rpm ftp://ftp.redhat.com/5.2/i386/netscape-navigator-4.73-0.5.2.i386.rpm ftp://ftp.redhat.com/5.2/i386/netscape-communicator-4.73-0.5.2.i386.rpm sources: ftp://ftp.redhat.com/5.2/SRPMS/netscape-4.73-0.5.2.src.rpm Red Hat Linux 6.2: intel: ftp://ftp.redhat.com/6.2/i386/netscape-common-4.73-1.i386.rpm ftp://ftp.redhat.com/6.2/i386/netscape-navigator-4.73-1.i386.rpm ftp://ftp.redhat.com/6.2/i386/netscape-communicator-4.73-1.i386.rpm alpha: ftp://ftp.redhat.com/6.2/alpha/netscape-common-4.73-1.alpha.rpm ftp://ftp.redhat.com/6.2/alpha/netscape-navigator-4.73-1.alpha.rpm ftp://ftp.redhat.com/6.2/alpha/netscape-communicator-4.73-1.alpha.rpm sources: ftp://ftp.redhat.com/6.2/SRPMS/netscape-4.73-1.src.rpm ftp://ftp.redhat.com/6.2/SRPMS/netscape-alpha-4.73-1.src.rpm 7. Verification: MD5 sum Package Name - -------------------------------------------------------------------------- 3e881194baf12d2d7e761a63041ba404 5.2/SRPMS/netscape-4.73-0.5.2.src.rpm 52498e09827f5e854f99e320e2923fc4 5.2/i386/netscape-common-4.73-0.5.2.i386.rpm 1e15dfb4454c36e7352cd1803974f871 5.2/i386/netscape-communicator-4.73-0.5.2.i386.rpm 703a4a0b80ca0c45967cb8cc569b0600 5.2/i386/netscape-navigator-4.73-0.5.2.i386.rpm a83932536aef2837be8733621c3415d0 6.2/SRPMS/netscape-4.73-1.src.rpm bb79a4d70ebc7ab6cd91c04fbb951ca8 6.2/SRPMS/netscape-alpha-4.73-1.src.rpm e800a7af7c20be924469aedb75ad807f 6.2/alpha/netscape-common-4.73-1.alpha.rpm 9502f4ec6d2c99f8f61329898f31450f 6.2/alpha/netscape-communicator-4.73-1.alpha.rpm d812be498d83e19dba903282c8805ee2 6.2/alpha/netscape-navigator-4.73-1.alpha.rpm de054f11902c5777446baff909da817c 6.2/i386/netscape-common-4.73-1.i386.rpm d3825c0c61838da0b35570fb0dc7e743 6.2/i386/netscape-communicator-4.73-1.i386.rpm aea9965093a8202196f637e8385035d9 6.2/i386/netscape-navigator-4.73-1.i386.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> 8. References: N/A - --------------------------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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