[RHSA-1999:029-01] Denial of service attack in in.telnetd

From: Bill Nottingham (nottingat_private)
Date: Thu Aug 19 1999 - 08:22:11 PDT

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    ---------------------------------------------------------------------
    		   Red Hat, Inc. Security Advisory
    
    Synopsis:		Denial of service attack in in.telnetd
    Advisory ID:		RHSA-1999:029-01
    Issue date:		1999-08-19
    Updated on:		
    Keywords:		telnet telnetd
    Cross references:
    ---------------------------------------------------------------------
    
    1. Topic:
    
    A denial of service attack has been fixed in in.telnetd.
    
    2. Bug IDs fixed (http://developer.redhat.com/bugzilla/):
    
    4560
    
    3. Relevant releases/architectures:
    
    Red Hat Linux 4.2, 5.2, 6.0, all architectures
    
    4. Obsoleted by:
    
    5. Conflicts with:
    
    6. RPMs required:
    
    Red Hat Linux 4.2:
    
    Intel:
      ftp://ftp.redhat.com/redhat/updates/4.2/i386/NetKit-B-0.09-11.i386.rpm
    
    Alpha:
      ftp://ftp.redhat.com/redhat/updates/4.2/alpha/NetKit-B-0.09-11.alpha.rpm
    
    Sparc:
      ftp://ftp.redhat.com/redhat/updates/4.2/sparc/NetKit-B-0.09-11.sparc.rpm
    
    Source packages:
      ftp://ftp.redhat.com/redhat/updates/4.2/SRPMS/NetKit-B-0.09-11.src.rpm
    
    Red Hat Linux 5.2:
    
    Intel:
      ftp://ftp.redhat.com/redhat/updates/5.2/i386/telnet-0.10-28.5.2.i386.rpm
    
    Alpha:
      ftp://ftp.redhat.com/redhat/updates/5.2/alpha/telnet-0.10-28.5.2.alpha.rpm
    
    Sparc:
      ftp://ftp.redhat.com/redhat/updates/5.2/sparc/telnet-0.10-28.5.2.sparc.rpm
    
    Source packages:
      ftp://ftp.redhat.com/redhat/updates/5.2/SRPMS/telnet-0.10-28.5.2.src.rpm
    
    Red Hat Linux 6.0:
    
    Intel:
      ftp://ftp.redhat.com/redhat/updates/6.0/i386/telnet-0.10-29.i386.rpm
    
    Alpha:
      ftp://ftp.redhat.com/redhat/updates/6.0/alpha/telnet-0.10-29.alpha.rpm
    
    Sparc:
      ftp://ftp.redhat.com/redhat/updates/6.0/sparc/telnet-0.10-29.sparc.rpm
    
    Source packages:
      ftp://ftp.redhat.com/redhat/updates/6.0/SRPMS/telnet-0.10-29.src.rpm
    
    7. Problem description:
    
    in.telnetd attempts to negotiate a compatible terminal type
    between the local and remote host. By setting the TERM
    environment variable before connecting, a remote user could
    cause the system telnetd to open files it should not. Depending
    on the TERM setting used, this could lead to denial of service
    attacks. 
    
    Thanks go to Michal Zalewski and the Linux Security Audit team
    for noting this vulnerability.
    
    8. Solution:
    
    For each RPM for your particular architecture, run:
     
    rpm -Uvh <filename>
     
    where filename is the name of the RPM.
    
    9. Verification:
    
    MD5 sum                           Package Name
    --------------------------------------------------------------------------
    0c425c34fb77a8309ff10b4143e9b847  i386/NetKit-B-0.09-11.i386.rpm
    d791d645adeb5fa0147c1058b21cbbac  alpha/NetKit-B-0.09-11.alpha.rpm
    bfbd440845191bbdcf8be21ee59bf6a8  sparc/NetKit-B-0.09-11.sparc.rpm
    ccd5ab53c423e468d66ca801c90b5ae4  SRPMS/NetKit-B-0.09-11.src.rpm
    
    ef33f3c5ca810d05420e57b5cfcf8928  i386/telnet-0.10-28.5.2.i386.rpm
    6dc23437a200193b0bfed23d5f5e6562  alpha/telnet-0.10-28.5.2.alpha.rpm
    49c38457cc0a82a680fd9b9634dc8021  sparc/telnet-0.10-28.5.2.sparc.rpm
    2f33670a683e3abef0e4914586c71961  SRPMS/telnet-0.10-28.5.2.src.rpm
    
    4360d47490f13d60b8737d28dc88825a  i386/telnet-0.10-29.i386.rpm
    90213fcdca41a3ed12ab7d92344e7286  alpha/telnet-0.10-29.alpha.rpm
    277787dbc39dff8ea84d4b16dcb7a954  sparc/telnet-0.10-29.sparc.rpm
    269783a0754d234f7bef0f4717a8dbc2  SRPMS/telnet-0.10-29.src.rpm
    
    These packages are PGP 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 --nopgp <filename>
    
    10. References:
    
    
    
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