Redhat: 'tcsh' symlink vulnerability
Posted by LinuxSecurity.com Team   
RedHat Linux Versions 6.09 and below of tcsh are vulnerable to a symbolic link attack.

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                   Red Hat, Inc. Security Advisory

Synopsis:          Updated tcsh packages are now available for Red Hat Linux.
Advisory ID:       RHSA-2000:121-04
Issue date:        2000-11-30
Updated on:        2000-12-01
Product:           Red Hat Linux
Keywords:          tcsh symlink vulnerability
Cross references:  N/A
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1. Topic:

Updated tcsh packages are now available for Red Hat Linux 5.2, 6.x, and 7.

2. Relevant releases/architectures:

Red Hat Linux 5.2 - i386, alpha, sparc
Red Hat Linux 6.0 - i386, alpha, sparc
Red Hat Linux 6.1 - i386, alpha, sparc
Red Hat Linux 6.2 - i386, alpha, sparc
Red Hat Linux 6.2EE - i386, alpha, sparc
Red Hat Linux 7.0 - i386, alpha
Red Hat Linux 7.0J - i386, alpha

3. Problem description:

Versions 6.09 and below of tcsh are vulnerable to a symbolic link attack. 
This attack can be used to cause users to destroy the contents of any file
to which they have write access.

4. Solution:

For each RPM for your particular architecture, run:

rpm -Fvh [filename]

where filename is the name of the RPM.

5. Bug IDs fixed  (http://bugzilla.Red Hat.com/bugzilla for more info):

20679 - tcsh '<<' security issue


6. RPMs required:

Red Hat Linux 5.2:

alpha: 
ftp://updates.Red Hat.com/5.2/alpha/tcsh-6.10-0.5.x.alpha.rpm

sparc: 
ftp://updates.Red Hat.com/5.2/sparc/tcsh-6.10-0.5.x.sparc.rpm

i386: 
ftp://updates.Red Hat.com/5.2/i386/tcsh-6.10-0.5.x.i386.rpm

sources: 
ftp://updates.Red Hat.com/5.2/SRPMS/tcsh-6.10-0.5.x.src.rpm

Red Hat Linux 6.0:

sparc: 
ftp://updates.Red Hat.com/6.0/sparc/tcsh-6.10-0.6.x.sparc.rpm

i386: 
ftp://updates.Red Hat.com/6.0/i386/tcsh-6.10-0.6.x.i386.rpm

alpha: 
ftp://updates.Red Hat.com/6.0/alpha/tcsh-6.10-0.6.x.alpha.rpm

sources: 
ftp://updates.Red Hat.com/6.0/SRPMS/tcsh-6.10-0.6.x.src.rpm

Red Hat Linux 6.1:

alpha: 
ftp://updates.Red Hat.com/6.1/alpha/tcsh-6.10-0.6.x.alpha.rpm

sparc: 
ftp://updates.Red Hat.com/6.1/sparc/tcsh-6.10-0.6.x.sparc.rpm

i386: 
ftp://updates.Red Hat.com/6.1/i386/tcsh-6.10-0.6.x.i386.rpm

sources: 
ftp://updates.Red Hat.com/6.1/SRPMS/tcsh-6.10-0.6.x.src.rpm

Red Hat Linux 6.2:

alpha: 
ftp://updates.Red Hat.com/6.2/alpha/tcsh-6.10-0.6.x.alpha.rpm

sparc: 
ftp://updates.Red Hat.com/6.2/sparc/tcsh-6.10-0.6.x.sparc.rpm

i386: 
ftp://updates.Red Hat.com/6.2/i386/tcsh-6.10-0.6.x.i386.rpm

sources: 
ftp://updates.Red Hat.com/6.2/SRPMS/tcsh-6.10-0.6.x.src.rpm

Red Hat Linux 7.0:

alpha: 
ftp://updates.Red Hat.com/7.0/alpha/tcsh-6.10-1.alpha.rpm

i386: 
ftp://updates.Red Hat.com/7.0/i386/tcsh-6.10-1.i386.rpm

sources: 
ftp://updates.Red Hat.com/7.0/SRPMS/tcsh-6.10-1.src.rpm

7. Verification:

MD5 sum                           Package Name
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ef09e7d86a3ea3805fed90b4e409ce78  5.2/SRPMS/tcsh-6.10-0.5.x.src.rpm
871a2d33370517380173c327d91deb83  5.2/alpha/tcsh-6.10-0.5.x.alpha.rpm
e228b2179d2917067a2267d08eb4f9f1  5.2/i386/tcsh-6.10-0.5.x.i386.rpm
8c839a90f05ab9acb4b83dc620aee644  5.2/sparc/tcsh-6.10-0.5.x.sparc.rpm
4eb03f6ac99e3e6f15fa8e0a7f680530  6.0/SRPMS/tcsh-6.10-0.6.x.src.rpm
1a05f99e1fe6d5ec091160ee8012cd07  6.0/alpha/tcsh-6.10-0.6.x.alpha.rpm
6c66a718122e2a0f79bb0f6218082ebc  6.0/i386/tcsh-6.10-0.6.x.i386.rpm
eda7e5af943795c2c85050724d8f5deb  6.0/sparc/tcsh-6.10-0.6.x.sparc.rpm
4eb03f6ac99e3e6f15fa8e0a7f680530  6.1/SRPMS/tcsh-6.10-0.6.x.src.rpm
1a05f99e1fe6d5ec091160ee8012cd07  6.1/alpha/tcsh-6.10-0.6.x.alpha.rpm
6c66a718122e2a0f79bb0f6218082ebc  6.1/i386/tcsh-6.10-0.6.x.i386.rpm
eda7e5af943795c2c85050724d8f5deb  6.1/sparc/tcsh-6.10-0.6.x.sparc.rpm
4eb03f6ac99e3e6f15fa8e0a7f680530  6.2/SRPMS/tcsh-6.10-0.6.x.src.rpm
1a05f99e1fe6d5ec091160ee8012cd07  6.2/alpha/tcsh-6.10-0.6.x.alpha.rpm
6c66a718122e2a0f79bb0f6218082ebc  6.2/i386/tcsh-6.10-0.6.x.i386.rpm
eda7e5af943795c2c85050724d8f5deb  6.2/sparc/tcsh-6.10-0.6.x.sparc.rpm
8237e14a4430f4ca48dd4421a049bf3d  7.0/SRPMS/tcsh-6.10-1.src.rpm
c4ce83f418496f40e3e802da03db3e6f  7.0/alpha/tcsh-6.10-1.alpha.rpm
1fee54c9b1fc394c03a8d960937a9747  7.0/i386/tcsh-6.10-1.i386.rpm

These packages are GPG signed by Red Hat, Inc. for security.  Our key
is available at:
     http://www.Red Hat.com/corp/contact.html

You can verify each package with the following command:
    rpm --checksig  

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 --nogpg 

8. References:
 
http://www.securityfocus.com/vdb/bottom.html?vid=1926


Copyright(c) 2000 Red Hat, Inc.