[comp.security.announce] CERT Advisory - DEC Ultrix chroot vulnerability

cert-advisory-request@CERT.SEI.CMU.EDU (CERT Advisory) (05/01/91)

CA-91:05                        CERT Advisory
                                 May 1, 1991
                        DEC Ultrix chroot Vulnerability

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The Computer Emergency Response Team/Coordination Center (CERT/CC) has
received information concerning a vulnerability in Digital Equipment 
Corporation's (DEC) Ultrix operating system versions 4.0 and 4.1 for all
DEC architectures.  The vulnerability has been fixed in version 4.2 which 
will be shipped beginning in late May.  DEC has also provided a suggested 
fix for versions 4.0 and 4.1.
  
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I.   DESCRIPTION:
     By default, /usr/bin/chroot is improperly installed in Ultrix 
     versions 4.0 and 4.1.
     
II.  IMPACT:
     System users can gain unauthorized privileges.

III. SOLUTION:
     Change the permission on the file /usr/bin/chroot.

     # chmod 700 /usr/bin/chroot    

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Our thanks to Eric R. Jorgensen and Brian Ellis of UnixOps / Distributed 
Computing Services at the University of Colorado, Boulder, for bringing this 
problem to our attention.  The CERT/CC would also like to thank Digital for 
their response to this vulnerability.
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If you believe that your system has been compromised, contact CERT/CC via
telephone or e-mail.

Computer Emergency Response Team/Coordination Center (CERT/CC)
Software Engineering Institute
Carnegie Mellon University
Pittsburgh, PA 15213-3890

Internet E-mail: cert@cert.sei.cmu.edu
Telephone: 412-268-7090 24-hour hotline:
           CERT/CC personnel answer 7:30a.m.-6:00p.m. EST,
           on call for emergencies during other hours.

Past advisories and other computer security related information are available
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