UnixWare 7.1.3 Open UNIX 8.0.0 UnixWare 7.1.1 : Insecure handling of procfs descriptors in UnixWare can lead to local privilege escalation.

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                        SCO Security Advisory

Subject:                UnixWare 7.1.3 Open UNIX 8.0.0 UnixWare 7.1.1 : Insecure handling of procfs descriptors in 
UnixWare can lead to local privilege escalation.
Advisory number:        CSSA-2003-SCO.32
Issue date:             2003 November 11
Cross reference:        sr886899 fz528474 erg712482
______________________________________________________________________________


1. Problem Description

        "/proc/$PID/as" Contains the address space image of process
        $PID. It can be opened and accessed like any other file and
        be used to manipulate the process. The process owner also
        owns the "as" file whose file permission is 600. 

        For obvious reasons this doesn't apply to processes spawned 
        from setuid and setgid binaries. This protection can be bypassed by
        first obtaining a descriptor to a process you own then let
        that process execve() a setuid binary. execve() will replace
        the process image, honor the setuid bit and the descriptor
        will remain open. 

        The Common Vulnerabilities and Exposures project (cve.mitre.org) 
        has assigned the name CAN-2003-0937 to this issue.


2. Vulnerable Supported Versions

        System                          Binaries
        ----------------------------------------------------------------------
        UnixWare 7.1.3                  /etc/conf/pack.d/procfs/Driver_atup.o
                                        /etc/conf/pack.d/procfs/Driver_mp.o

        Open UNIX 8.0.0                 /etc/conf/pack.d/procfs/Driver_atup.o
        (aka UnixWare 7.1.2)            /etc/conf/pack.d/procfs/Driver_mp.o

        UnixWare 7.1.1                  /etc/conf/pack.d/procfs/Driver_atup.o
                                        /etc/conf/pack.d/procfs/Driver_mp.o
                                        
3. Solution

        The proper solution is to install the latest packages.


4. UnixWare 7.1.3

        4.1 Location of Fixed Binaries

        ftp://ftp.sco.com/pub/updates/UnixWare/CSSA-2003-SCO.32

        erg712482c should only be installed on: UnixWare 7.1.3

        4.2 Verification

        MD5 (erg712482c.Z) = 50c98884a6dcb14ccf57d71aad135045

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

        4.3 Installing Fixed Binaries

        Upgrade the affected binaries with the following sequence:

        1. Download the erg712482c.Z file to the /tmp directory on your machine.

        2. As root, uncompress the file and add the package to your system
        using these commands:

        $ su
        Password: <type your root password>
        # uncompress /tmp/erg712482c.Z
        # pkgadd -d /tmp/erg712482c
        # rm /tmp/erg712482c

        Alternatively, this SLS package may be installed in quiet mode,
        that is, without displaying the release notes and asking for
        confirmation.  To do this, use these commands:

        $ su
        Password: <type your root password>
        # uncompress /tmp/erg712482c.Z
        # pkgadd -qd /tmp/erg712482c all
        # rm /tmp/erg712482c

        3. Reboot the system after installing this package.


        Removal Instructions
        --------------------

        1. As root, remove the package using these commands:

        $ su
        Password: <type your root password>
        # pkgrm erg712482

        2. Reboot the system after removing this package.


5. Open UNIX 8.0.0

        5.1 Location of Fixed Binaries

        ftp://ftp.sco.com/pub/updates/UnixWare/CSSA-2003-SCO.32

        erg712482b should only be installed on: UnixWare 7.1.2 or Open UNIX 8.0.0

        5.2 Verification

        MD5 (erg712482b.Z) = 54d3568e631d4739034815537242dc0d

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

        5.3 Installing Fixed Binaries

        Upgrade the affected binaries with the following sequence:

        1. Download the erg712482b.Z file to the /tmp directory on your machine.

        2. As root, uncompress the file and add the package to your system
           using these commands:

        $ su
        Password: <type your root password>
        # uncompress /tmp/erg712482b.Z
        # pkgadd -d /tmp/erg712482b
        # rm /tmp/erg712482b

        Alternatively, this SLS package may be installed in quiet mode,
        that is, without displaying the release notes and asking for
        confirmation.  To do this, use these commands:

        $ su
        Password: <type your root password>
        # uncompress /tmp/erg712482b.Z
        # pkgadd -qd /tmp/erg712482b all
        # rm /tmp/erg712482b

        3. Reboot the system after installing this package.

        Removal Instructions
        --------------------

        1. As root, remove the package using these commands:

        $ su
        Password: <type your root password>
        # pkgrm erg712482

        2. Reboot the system after removing this package.


6. UnixWare 7.1.1

        6.1 Location of Fixed Binaries

        ftp://ftp.sco.com/pub/updates/UnixWare/CSSA-2003-SCO.32

        erg712482a should only be installed on: UnixWare 7.1.1

        6.2 Verification

        MD5 (erg712482a.Z) = 15776bcbaf01155eb28087ee213fecf8

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


        6.3 Installing Fixed Binaries

        Upgrade the affected binaries with the following sequence:

        erg712482a should only be installed on: UnixWare 7.1.1

        1. Download the erg712482a.Z file to the /tmp directory on your machine.

        2. As root, uncompress the file and add the package to your system
           using these commands:

        $ su
        Password: <type your root password>
        # uncompress /tmp/erg712482a.Z
        # pkgadd -d /tmp/erg712482a
        # rm /tmp/erg712482a

        Alternatively, this SLS package may be installed in quiet mode,
        that is, without displaying the release notes and asking for
        confirmation.  To do this, use these commands:

        $ su
        Password: <type your root password>
        # uncompress /tmp/erg712482a.Z
        # pkgadd -qd /tmp/erg712482a all
        # rm /tmp/erg712482a

        3. Reboot the system after installing this package.


        Removal Instructions
        --------------------

        1. As root, remove the package using these commands:

        $ su
        Password: <type your root password>
        # pkgrm erg712482

        2. Reboot the system after removing this package.


7. References

        Specific references for this advisory:
                http://www.texonet.com/advisories/TEXONET-20031024.txt
                http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2003-0937

        SCO security resources:
                http://www.sco.com/support/security/index.html

        This security fix closes SCO incidents sr886899 fz528474
        erg712482.


8. Disclaimer

        SCO 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 SCO
        products.


9. Acknowledgments

        SCO would like to thank Joel Soderberg and Christer Oberg
        from Texonet. Texonet is a Swedish based security company
        with a focus on penetration testing / security assessments,
        research and development.
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