dcsimg
Linux Today: Linux News On Internet Time.





More on LinuxToday


Caldera Security Advisory: Linux - Telnet AYT remote exploit

Aug 14, 2001, 06:55 (0 Talkback[s])
Date: Mon, 13 Aug 2001 17:45:59 -0600
From: Support Info <supinfo@caldera.com>
Subject: Security Update: [CSSA-2001-30.0] Linux - Telnet AYT remote exploit

____________________________________________________________________________
                   Caldera International, Inc.  Security Advisory

Subject:                Linux - Telnet AYT remote exploit
Advisory number:        CSSA-2001-030.0
Issue date:             2001, August 10
Cross reference:
____________________________________________________________________________


1. Problem Description

   Recently, a security problem was discovered in various BSD derived
   implementations of the telnet daemon. Initially, it was thought that
   the Linux netkit-telnet was not vulnerable to this problem. It turne
   out that this was wrong.

   On OpenLinux previous to version 3.1, this bug allows remote attackers
   to gain root privilege.

   Starting with OpenLinux 3.1, the telnet daemon is split into
   two processes, a privileged one running the login session, and a
   restricted one handling the network protocol where the bug occurs. As
   a consequence, attempts to exploit this problem on OpenLinux 3.1 will
   give an attacker a process running as user "nobody", and confined to
   an empty chroot directory.


2. Vulnerable Versions

   System                       Package
   -----------------------------------------------------------
   OpenLinux 2.3                 All packages previous to      
                                 netkit-telnet-0.17-12a        
   
   OpenLinux eServer 2.3.1       All packages previous to      
   and OpenLinux eBuilder        netkit-telnet-0.17-12a        
   
   OpenLinux eDesktop 2.4        All packages previous to      
                                 netkit-telnet-0.17-12a        
   
   OpenLinux Server 3.1          All packages previous to      
                                 netkit-telnet-0.17-12         
   
   OpenLinux Workstation 3.1     All packages previous to      
                                 netkit-telnet-0.17-12         
   

3. Solution

   Workaround

     none

   The proper solution is to upgrade to the latest packages.

4. OpenLinux 2.3

    4.1 Location of Fixed Packages

       The upgrade packages can be found on Caldera's FTP site at:

       ftp://ftp.caldera.com/pub/updates/OpenLinux/2.3/current/RPMS

       The corresponding source code package can be found at:

       ftp://ftp.caldera.com/pub/updates/OpenLinux/2.3/current/SRPMS

   4.2 Verification

       70f6d9fd0083167b23c0f22043b5f72c  RPMS/netkit-telnet-0.17-12a.i386.rpm
       394490b87437bd04ca4aff661c4f5fff  SRPMS/netkit-telnet-0.17-12a.src.rpm
       

   4.3 Installing Fixed Packages

       Upgrade the affected packages with the following commands:

         rpm -Fvh netkit-telnet-0.17-12a.i386.rpm
         

5. OpenLinux eServer 2.3.1 and OpenLinux eBuilder for ECential 3.0

    5.1 Location of Fixed Packages

       The upgrade packages can be found on Caldera's FTP site at:

       ftp://ftp.caldera.com/pub/updates/eServer/2.3/current/RPMS

       The corresponding source code package can be found at:

       ftp://ftp.caldera.com/pub/updates/eServer/2.3/current/SRPMS

   5.2 Verification

       82e95fe89d065e3116253701004de600  RPMS/netkit-telnet-0.17-12a.i386.rpm
       394490b87437bd04ca4aff661c4f5fff  SRPMS/netkit-telnet-0.17-12a.src.rpm
       

   5.3 Installing Fixed Packages

       Upgrade the affected packages with the following commands:

         rpm -Fvh netkit-telnet-0.17-12a.i386.rpm
         

6. OpenLinux eDesktop 2.4

    6.1 Location of Fixed Packages

       The upgrade packages can be found on Caldera's FTP site at:

       ftp://ftp.caldera.com/pub/updates/eDesktop/2.4/current/RPMS

       The corresponding source code package can be found at:

       ftp://ftp.caldera.com/pub/updates/eDesktop/2.4/current/SRPMS

   6.2 Verification

       e35ae266e108a9494f8dd89f96e4b889  RPMS/netkit-telnet-0.17-12a.i386.rpm
       394490b87437bd04ca4aff661c4f5fff  SRPMS/netkit-telnet-0.17-12a.src.rpm
       

   6.3 Installing Fixed Packages

       Upgrade the affected packages with the following commands:

         rpm -Fvh netkit-telnet-0.17-12a.i386.rpm
         

7. OpenLinux 3.1 Server

    7.1 Location of Fixed Packages

       The upgrade packages can be found on Caldera's FTP site at:

       ftp://ftp.caldera.com/pub/updates/OpenLinux/3.1/Server/current/RPMS

       The corresponding source code package can be found at:

       ftp://ftp.caldera.com/pub/updates/OpenLinux/3.1/Server/current/SRPMS

   7.2 Verification

       498c44cc801022653ee6c692a8633d74  RPMS/netkit-telnet-0.17-12.i386.rpm
       ddd8cf299465d84d1044a13b8e340a23  SRPMS/netkit-telnet-0.17-12.src.rpm
       

   7.3 Installing Fixed Packages

       Upgrade the affected packages with the following commands:

         rpm -Fvh netkit-telnet-0.17-12.i386.rpm
        
       or start kcupdate, the Caldera OpenLinux Update Manager.

8. OpenLinux 3.1 Workstation

    8.1 Location of Fixed Packages

       The upgrade packages can be found on Caldera's FTP site at:

       ftp://ftp.caldera.com/pub/updates/OpenLinux/3.1/Workstation/current/RPMS

       The corresponding source code package can be found at:

       ftp://ftp.caldera.com/pub/updates/OpenLinux/3.1/Workstation/current/SRPMS

   8.2 Verification

       498c44cc801022653ee6c692a8633d74  RPMS/netkit-telnet-0.17-12.i386.rpm
       ddd8cf299465d84d1044a13b8e340a23  SRPMS/netkit-telnet-0.17-12.src.rpm
       

   8.3 Installing Fixed Packages

       Upgrade the affected packages with the following commands:

         rpm -Fvh netkit-telnet-0.17-12.i386.rpm

       or start kcupdate, the Caldera OpenLinux Update Manager.
         

9. References

   This and other Caldera security resources are located at:

   http://www.caldera.com/support/security/index.html

   This security fix closes Caldera's internal Problem Report 10351.


10. 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 OpenLinux.

11. Acknowledgements

   Caldera wishes to thank Zen-Parse (zen-parse@gmx.net) for advance
   notification of this bug and his cooperation.