home *** CD-ROM | disk | FTP | other *** search
- ***********************************************************************
- DDN Security Bulletin 9108 DCA DDN Defense Communications System
- 23 MAY 91 Published by: DDN Security Coordination Center
- (SCC@NIC.DDN.MIL) (800) 235-3155
-
- DEFENSE DATA NETWORK
- SECURITY BULLETIN
-
- The DDN SECURITY BULLETIN is distributed by the DDN SCC (Security
- Coordination Center) under DCA contract as a means of communicating
- information on network and host security exposures, fixes, & concerns
- to security & management personnel at DDN facilities. Back issues may
- be obtained via FTP (or Kermit) from NIC.DDN.MIL [192.67.67.20]
- using login="anonymous" and password="guest". The bulletin pathname is
- SCC:DDN-SECURITY-yynn (where "yy" is the year the bulletin is issued
- and "nn" is a bulletin number, e.g. SCC:DDN-SECURITY-9001).
- **********************************************************************
-
- AT&T System V Release 4 /bin/login Vulnerability
-
- + - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - +
- ! !
- ! The following important advisory was issued by the Computer !
- ! Emergency Response Team (CERT) and is being relayed unedited !
- ! via the Defense Communications Agency's Security Coordination !
- ! Center distribution system as a means of providing DDN !
- ! subscribers with useful security information. !
- ! !
- + - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - +
-
-
-
- CA-91:08 CERT Advisory
- May 23, 1991
- AT&T System V Release 4 /bin/login Vulnerability
-
- ---------------------------------------------------------------------------
-
- 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.
-
- ---------------------------------------------------------------------------
- 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.
-
- ---------------------------------------------------------------------------
- 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 (128.237.253.5) system.
-
-
-