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- CA-91:08 CERT Advisory
- May 23, 1991
- AT&T System V Release 4 /bin/login Vulnerability
-
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-
- The Computer Emergency Response Team/Coordination Center (CERT/CC) has
- received information concerning a security vulnerability in AT&T's UNIX(r)
- System V Release 4 operating system. AT&T is providing a software upgrade
- for Release 4 operating system vendors and a patch for AT&T Computer Systems
- customers. AT&T has also provided a suggested fix for all Release 4
- based systems.
-
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- I. DESCRIPTION:
-
- A security vulnerability exists in /bin/login in AT&T's System V
- Release 4 operating system.
-
-
- II. IMPACT:
-
- System users can gain unauthorized privileges.
-
-
- III. SOLUTION:
-
- A. AT&T Computer Systems customers
-
- Log into the root account. Change the execution permission on
- the file /bin/login.
-
- chmod 500 /bin/login
-
- Contact AT&T Computer Systems at 800-922-0354 to obtain a fix.
- The numbers associated with the fix are 156 (3.5" media) and
- 157 (5.25" media).
-
- International customers should contact their local AT&T
- Computer Systems representative.
-
- B. All other System V Release 4 based systems
-
- Log into the root account. Change the execution permission on
- the file /bin/login.
-
- chmod 500 /bin/login
-
- Release 4 customers should contact their operating system
- supplier for details on the availability of the software
- update.
-
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- The CERT/CC would like to thank AT&T for their timely response to our
- report of this vulnerability.
- ---------------------------------------------------------------------------
-
- 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
- for anonymous ftp from the cert.sei.cmu.edu (192.88.209.5) system.
-