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- ===========================================================================
- CA-91:23 CERT Advisory
- December 18, 1991
- Hewlett Packard/Apollo Domain/OS crp Vulnerability
- ---------------------------------------------------------------------------
-
- The Computer Emergency Response Team/Coordination Center (CERT/CC)
- has received information concerning a vulnerability in the crp facility
- in Hewlett Packard/Apollo Domain/OS. This vulnerability is present on all
- HP/Apollo Domain/OS SR10 systems up through SR10.3. Patches that address
- this problem will be available in the SR10.3 patch tape (~Feb 92) and in
- the SR10.4 software release. Contact your local sales office for
- more information.
-
- ---------------------------------------------------------------------------
-
- I. Description
-
- There is a security problem with the /usr/apollo/bin/crp facility.
- A user who is not running crp is not vulnerable to this problem.
-
- II. Impact
-
- A person at a remote or local site can obtain the privileges of
- the user who is running crp.
-
- III. Workaround
-
- The suggested workaround is to disable two system calls that are
- made by /usr/apollo/bin/crp. The following steps should be
- executed by root or another appropriate userid that has the
- privilege to write in the directories involved.
-
- 1. Create a file "crplib.c" containing the four-line C program:
-
- extern void pad_$dm_cmd(void);
- void pad_$dm_cmd() { }
- extern void pad_$def_pfk(void);
- void pad_$def_pfk() { }
-
- 2. Compile this program using '-pic':
-
- (AEGIS) /com/cc crplib.c -pic
- (UNIX) /bin/cc -c crplib.c -W0,-pic
-
- 3. Copy the result to somewhere accessible to all users (/lib/crplib
- is recommended).
-
- (AEGIS) /com/cpf crplib.bin /lib/crplib
- (AEGIS) /com/edacl -p root prwx -g wheel rx -w rx /lib/crplib
-
- (UNIX) /bin/cp crplib.o /lib/crplib
- (UNIX) /bin/chmod 755 /lib/crplib
-
- 4. a) Ensure that all users do an 'inlib' of that file before running crp.
- One way to ensure this would be to replace the /usr/apollo/bin/crp
- command by a shell script that does the inlib. Doing this step
- will force crp to use the null functions defined in step 1 above.
-
- (AEGIS) /com/chn /usr/apollo/bin/crp crp.orig
- (UNIX) /bin/mv /usr/apollo/bin/crp /usr/apollo/bin/crp.orig
-
- b) Create the file /usr/apollo/bin/crp containing the shell script:
-
- (AEGIS) #!/com/sh
- /com/sh -c inlib /lib/crplib ';' /usr/apollo/bin/crp.orig ^*
-
- (UNIX) #!/bin/sh
- inlib /lib/crplib
- exec /usr/apollo/bin/crp.orig "$@"
-
- c) Make this script executable.
-
- (AEGIS) /com/edacl -p root prwx -g wheel rx -w rx /usr/apollo/bin/crp
- (UNIX) /bin/chmod 755 /usr/apollo/bin/crp
-
- ---------------
-
- NOTE: This workaround will prevent crp from making use of the two
- system calls; and therefore, it may affect the functionality of various
- software programs since they will be unable to define programmable
- function keys, create new windows on the client node, or execute
- background processes using the Display Manager interface.
-
- ---------------------------------------------------------------------------
- The CERT/CC wishes to thank Paul Szabo of the University of Sydney for
- bringing this problem to our attention and providing a workaround.
- We would also like to thank Jim Richardson of the University of Sydney for
- his assistance and Hewlett Packard/Apollo for their timely response to the
- report of this vulnerability.
- ---------------------------------------------------------------------------
-
- If you believe that your system has been compromised, contact CERT/CC via
- telephone or e-mail.
-
- 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(GMT-5)/EDT(GMT-4),
- on call for emergencies during other hours.
-
- Computer Emergency Response Team/Coordination Center (CERT/CC)
- Software Engineering Institute
- Carnegie Mellon University
- Pittsburgh, PA 15213-3890
-
- Past advisories and other information related to computer security are
- available for anonymous ftp from the cert.sei.cmu.edu (192.88.209.5) system.
-
-