To: bugtraq@securityfocus.com announce@lists.caldera.com scoannmod@xenitec.on.ca 

___________________________________________________________________________

            Caldera International, Inc. Security Advisory

Subject:                OpenServer: IPFilter may incorrectly pass packets
Advisory number:        CSSA-2002-SCO.9
Issue date:             2002 March 11
Cross reference:
___________________________________________________________________________


1. Problem Description

        When matching a packet fragment, insufficient checks were
        performed to ensure the fragment is valid.  Malicious remote
        users may be able to bypass filtering rules, allowing them to
        potentially circumvent the firewall.


2. Vulnerable Supported Versions

        Operating System        Version         Affected Files
        ------------------------------------------------------------------
        OpenServer              <= 5.0.6a       /etc/ipnat
                                                /etc/ipfnat
                                                /etc/conf/pack.d/ipl/Driver.o
                                                /etc/ipmon
                                                /etc/ipfstat
                                                /etc/ipf


3. Workaround

        None.


4. OpenServer

  4.1 Location of Fixed Binaries

        ftp://stage.caldera.com/pub/security/openserver/CSSA-2002-SCO.9/


  4.2 Verification

        MD5 (erg711678) = 7608023bdd367331a8088a92b114db5c

        md5 is available for download from
                ftp://stage.caldera.com/pub/security/tools/


  4.3 Installing Fixed Binaries

        Upgrade the affected binaries with the following commands:

        Download erg711678 to the /tmp directory

        # cd /tmp
        # tar xvf erg711678

        Run the custom command, specify an install from media images,
        and specify the /tmp directory as the location of the images.


5. References

        This and other advisories are located at
                http://stage.caldera.com/support/security

        This advisory addresses Caldera Security internal incidents
        SCO-236-1763, erg711678


6. Disclaimer

        Caldera International, Inc. is not responsible for the misuse
        of any of the information we provide on our website and/or
        through our security advisories. Our advisories are a service
        to our customers intended to promote secure installation and
        use of Caldera International products.


7. Acknowledgements

        Caldera would like to admit borrowing the problem description
        text from FreeBSD security advisory FreeBSD-SA-01:32.