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- ===========================================================================
- CA-91:20 CERT Advisory
- October 22, 1991
- /usr/ucb/rdist Vulnerability
-
- ---------------------------------------------------------------------------
-
- The Computer Emergency Response Team/Coordination Center (CERT/CC) has
- received information concerning a vulnerability in /usr/ucb/rdist (the
- location of rdist may vary depending on the operating system). This
- vulnerability is present in possibly all versions of rdist. Vendors
- responding with patches are listed below. Additionally, some vendors
- who do not include rdist in their operating systems are identified.
- Operating systems from vendors not listed in either of the two categories
- below will probably be affected and the CERT/CC has proposed a workaround
- for those systems.
-
- VENDORS THAT DO NOT SHIP rdist
- (Note: Even though these vendors do not ship rdist, it may have been
- added later (for example, by the system administrator). It is
- also possible that vendors porting one of these operating systems
- may have added rdist. In both cases corrective action must be taken.)
-
- Amdahl
- AT&T System V
- Data General DG/UX for AViiON Systems
-
-
- VENDORS PROVIDING PATCHES
-
- Cray Research, Inc. UNICOS 6.0/6.E/6.1 Field Alert #132 SPR 47600
-
- For further information contact the Support Center at 1-800-950-CRAY or
- 612-683-5600 or e-mail support@crayamid.cray.com.
-
- NeXT Computer, Inc. NeXTstep Release 2.x
-
- A new version of rdist may be obtained from your
- authorized NeXT Support Center. If you are an authorized
- support center, please contact NeXT through your normal
- channels. NeXT also plans to make this new version of
- rdist available on the public NeXT FTP archives.
-
- Silicon Graphics IRIX 3.3.x/4.0 (fixed in 4.0.1)
-
- Patches may be obtained via anonymous ftp from sgi.com in the
- sgi/rdist directory.
-
- Sun Microsystems, Inc. SunOS 4.0.3/4.1/4.1.1 Patch ID 100383-02
-
- Patches may be obtained via anonymous ftp from ftp.uu.net or from local
- Sun Answer Centers worldwide.
-
-
- The CERT/CC is hopeful that other patches will be forthcoming. We will
- be maintaining a status file, rdist-patch-status, on the cert.org
- system. We will add patch availability information to this file as
- it becomes known. The file is available via anonymous ftp to
- cert.org and is found in pub/cert_advisories/rdist-patch-status.
-
- All trademarks are the property of their respective holders.
- ---------------------------------------------------------------------------
-
- I. Description
-
- A security vulnerability exists in /usr/ucb/rdist that
- can be used to gain unauthorized privileges. Under some
- circumstances /usr/ucb/rdist can be used to create setuid
- root programs.
-
- II. Impact
-
- Any user logged into the system can gain root access.
-
- III. Solution
-
- A. If available, install the appropriate patch provided by
- your operating system vendor.
-
- B. If no patch is available, restrict the use of /usr/ucb/rdist
- by changing the permissions on the file.
-
- # chmod 711 /usr/ucb/rdist
-
- ---------------------------------------------------------------------------
- The CERT/CC wishes to thank Casper Dik of the University of Amsterdam,
- The Netherlands, for bringing this vulnerability to our attention.
- We would also like to thank the vendors who have responded to this problem.
- ---------------------------------------------------------------------------
-
- 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.org
- Telephone: 412-268-7090 24-hour hotline:
- CERT/CC personnel answer 7:30a.m.-6:00p.m. EST(GMT-5)/EDT(GMT-4),
- on call for emergencies during other hours.
-
- Past advisories and other computer security related information are available
- for anonymous ftp from the cert.org (192.88.209.5) system.
-