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Security Update: [CSSA-2002-SCO.23] Open UNIX 8.0.0 UnixWare 7.1.1 : ftpd allows data connection hijacking via PASV mode


From: security () caldera com
Date: Thu, 30 May 2002 11:30:43 -0700

To: bugtraq () securityfocus com announce () lists caldera com scoannmod () xenitec on ca 

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                Caldera International, Inc.  Security Advisory

Subject:                Open UNIX 8.0.0 UnixWare 7.1.1 : ftpd allows data connection hijacking via PASV mode
Advisory number:        CSSA-2002-SCO.23
Issue date:             2002 May 30
Cross reference:
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1. Problem Description

        In FTP PASV mode, the client makes a control connection to the
        FTP server (typically port 21/tcp) and requests a PASV data
        connection. The server responds by listening for client
        connections on a specified port number, which is supplied to
        the client via the control connection. If an attacker can make
        a connection to the listening port before the client connects,
        the server will transmit the data to the attacker instead of
        the client.

        To exploit this vulnerability, the attacker must intercept or
        guess the port number that the server will use, then make its
        connection attempt before the client establishes a data
        connection. If the server chooses port numbers using an easily
        identifiable pattern (such as incrementally), this
        vulnerability is trivial to exploit.


2. Vulnerable Supported Versions

        System                          Binaries
        ----------------------------------------------------------------------
        Open UNIX 8.0.0                 /usr/sbin/in.ftpd
        UnixWare 7.1.1                  /usr/sbin/in.ftpd


3. Solution

        The proper solution is to install the latest packages.


4. Open UNIX 8.0.0

        4.1 Location of Fixed Binaries

        ftp://stage.caldera.com/pub/security/openunix/CSSA-2002-SCO.23


        4.2 Verification

        MD5 (erg501602b.pkg.Z) = e25467ff65349f5f388698fdd39161b5

        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 erg501602b.pkg.Z to the /var/spool/pkg directory

        # uncompress /var/spool/pkg/erg501602b.pkg.Z
        # pkgadd -d /var/spool/pkg/erg501602b.pkg


5. UnixWare 7.1.1

        5.1 Location of Fixed Binaries

        ftp://stage.caldera.com/pub/security/openunix/CSSA-2002-SCO.23


        5.2 Verification

        MD5 (erg501602b.pkg.Z) = e25467ff65349f5f388698fdd39161b5

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


        5.3 Installing Fixed Binaries

        Upgrade the affected binaries with the following commands:

        Download erg501602b.pkg.Z to the /var/spool/pkg directory

        # uncompress /var/spool/pkg/erg501602b.pkg.Z
        # pkgadd -d /var/spool/pkg/erg501602b.pkg


6. References

        Specific references for this advisory:
                http://www.kb.cert.org/vuls/id/2558

        Caldera UNIX security resources:
                http://stage.caldera.com/support/security/

        Caldera OpenLinux security resources:
                http://www.caldera.com/support/security/index.html

        This security fix closes Caldera incidents sr863902, fz520882,
        erg501602.


7. Disclaimer

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

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