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______________________________________________________________________________
Silicon Graphics Inc. Security Advisory
Title: IRIX 6.3 & 6.4 mailcap vulnerability
Number: 19980403-01-PX
Date: April 2, 1998
______________________________________________________________________________
Silicon Graphics provides this information freely to the SGI user community
for its consideration, interpretation, implementation and use. Silicon
Graphics recommends that this information be acted upon as soon as possible.
Silicon Graphics provides the information in this Security Advisory on
an "AS-IS" basis only, and disclaims all warranties with respect thereto,
express, implied or otherwise, including, without limitation, any warranty
of merchantability or fitness for a particular purpose. In no event shall
Silicon Graphics be liable for any loss of profits, loss of business, loss
of data or for any indirect, special, exemplary, incidental or consequential
damages of any kind arising from your use of, failure to use or improper
use of any of the instructions or information in this Security Advisory.
______________________________________________________________________________
- -----------------------
- --- Issue Specifics ---
- -----------------------
The System Manager sysmgr(1M) provides a web-browser-like GUI interface to
tasks that help you administer an SGI workstation. sysmgr(1M) uses multiple
tools to manage its GUI interface, two of them being runtask(1M) and
runexec(1M).
By mimicking the descriptor files of runtask(1M) or runexec(1M), an SGI user
browsing web pages or reading email can inadvertently download a
"trojan horse" runtask(1M) or runexec(1M) descriptor file. The "trojan horse"
descriptor file will execute a local System Manager Task with the privileges
of the user web browsing and can lead to a local root compromise.
Silicon Graphics Inc. has investigated the issue and recommends the
following steps for neutralizing the exposure. It is HIGHLY RECOMMENDED
that these measures be implemented on ALL vulnerable SGI systems. This
issue will be corrected in future releases of IRIX.
- --------------
- --- Impact ---
- --------------
All IRIX 6.3/6.4 users that have Mailcap entries for x-sgi-task
and x-sgi-exec have this vulnerability. On IRIX 6.3/6.4, these vulnerable
Mailcap entries are installed by default in /usr/local/lib/netscape/mailcap .
Users can add their own Mailcap entries in their home directories
($HOME/.mailcap) and these need to be inspected for the vulnerable x-sgi-task
and x-sgi-exec entries.
By default, this vulnerability requires an IRIX 6.3/6.4 user to use
Netscape Navigator to web browse or read email from a malicious site
and download a "trojan horse" System Manager Task which will execute
locally with the privileges of the user web browsing. If the user is a
privileged or root user, the "trojan horse" System Manger Task will execute
with root privileges and can lead to a root compromise.
- --------------------------
- --- Temporary Solution ---
- --------------------------
Although patches are available for this issue, it is realized that
there may be situations where installing the patches immediately may
not be possible.
1) Become the root user on the system.
% /bin/su -
Password:
#
2) Edit the default Mailcap file.
# vi /usr/local/lib/netscape/mailcap
3) Remove the following vulnerable mailcap entries:
application/x-sgi-task; /usr/sysadm/bin/runtask %s; \
description="System Administration Task"
application/x-sgi-exec; /usr/sysadm/bin/runexec %s; \
description="System Administration Executable"
4) Find any additional mailcap files and remove any vulnerable entries.
You will need to run the find(1) command on each system you
maintain because the command examines files on local disks only.
Note that this is one long command, though we have separated it
onto three lines using backslashes.
# find / -local -type f -name 'mailcap' -o \
-name '.mailcap' -exec egrep 'runexec|runtask' {} \
/dev/null \;
This command will find all files on a system that:
are only in the local file system (/ -local)
are regular files (-type f)
have the name "mailcap" (-name 'mailcap') or the name ".mailcap"
Once found, those files will be searched for the string "runexec" or
"runtask" (-exec egrep 'runexec|runtask' {}) and have their path names
printed .
The addition of /dev/null as an argument causes grep to list the
full pathname of any file containing the string, rather than just the
basename.
Edit the files that have the pathnames printed and remove any
vulnerable runtask/runexec mailcap entries.
5) Return to previous level.
# exit
$
- ----------------
- --- Solution ---
- ----------------
OS Version Vulnerable? Patch # Other Actions
---------- ----------- ------- -------------
IRIX 3.x no
IRIX 4.x no
IRIX 5.0.x no
IRIX 5.1.x no
IRIX 5.2 no
IRIX 5.3 no
IRIX 6.0.x no
IRIX 6.1 no
IRIX 6.2 no
IRIX 6.3 yes 2336
IRIX 6.4 yes 2339
Patches are available via anonymous FTP and your service/support provider.
The SGI anonymous FTP site is sgigate.sgi.com (204.94.209.1) or its
mirror, ftp.sgi.com. Security information and patches can be found
in the ~ftp/security and ~ftp/patches directories, respectfully.
##### Patch File Checksums ####
The actual patch will be a tar file containing the following files:
Filename: README.patch.2336
Algorithm #1 (sum -r): 15417 8 README.patch.2336
Algorithm #2 (sum): 21104 8 README.patch.2336
MD5 checksum: C5FCA39F205EF1C306F28E95C811150C
Filename: patchSG0002336
Algorithm #1 (sum -r): 64988 2 patchSG0002336
Algorithm #2 (sum): 38657 2 patchSG0002336
MD5 checksum: C38D6B81878377F470D1CC0ED43C8227
Filename: patchSG0002336.idb
Algorithm #1 (sum -r): 05931 2 patchSG0002336.idb
Algorithm #2 (sum): 54651 2 patchSG0002336.idb
MD5 checksum: 0C821C1BC07C08F279288F86E9807C93
Filename: patchSG0002336.netscape_gold_sw
Algorithm #1 (sum -r): 52912 20 patchSG0002336.netscape_gold_sw
Algorithm #2 (sum): 51500 20 patchSG0002336.netscape_gold_sw
MD5 checksum: 88CABDD9E4669CC6303876D77E491E4F
Filename: README.patch.2339
Algorithm #1 (sum -r): 11695 8 README.patch.2339
Algorithm #2 (sum): 21823 8 README.patch.2339
MD5 checksum: 114563D0D67F80E371C71EF3E6262900
Filename: patchSG0002339
Algorithm #1 (sum -r): 37814 2 patchSG0002339
Algorithm #2 (sum): 40753 2 patchSG0002339
MD5 checksum: E0B519F8ECD83396E29DFE07DF23517E
Filename: patchSG0002339.idb
Algorithm #1 (sum -r): 59311 2 patchSG0002339.idb
Algorithm #2 (sum): 54667 2 patchSG0002339.idb
MD5 checksum: 8E39530FD44C9087F0C07B1F75043764
Filename: patchSG0002339.netscape_gold_sw
Algorithm #1 (sum -r): 39233 20 patchSG0002339.netscape_gold_sw
Algorithm #2 (sum): 53498 20 patchSG0002339.netscape_gold_sw
MD5 checksum: 7FF56E22472B0797499920BAAB8CA9C5
- - ------------------------
- - --- Acknowledgments ---
- - ------------------------
Silicon Graphics wishes to thank the CERT Coordination Center, and
AUSCERT for their assistance in this matter.
- - -----------------------------------------------------------
- - --- Silicon Graphics Inc. Security Information/Contacts ---
- - -----------------------------------------------------------
If there are questions about this document, email can be sent to
cse-security-alert@sgi.com.
------oOo------
Silicon Graphics provides security information and patches for
use by the entire SGI community. This information is freely
available to any person needing the information and is available
via anonymous FTP and the Web.
The primary SGI anonymous FTP site for security information and patches
is sgigate.sgi.com (204.94.209.1). Security information and patches
are located under the directories ~ftp/security and ~ftp/patches,
respectively. The Silicon Graphics Security Headquarters Web page is
accessible at the URL http://www.sgi.com/Support/security/security.html.
For issues with the patches on the FTP sites, email can be sent to
cse-security-alert@sgi.com.
For assistance obtaining or working with security patches, please
contact your SGI support provider.
------oOo------
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released. Subscribing to the mailing list can be done via the Web
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% mail wiretap-request@sgi.com
subscribe wiretap <YourEmailAddress>
end
^d
In the example above, <YourEmailAddress> is the email address that you
wish the mailing list information sent to. The word end must be on a
separate line to indicate the end of the body of the message. The
control-d (^d) is used to indicate to the mail program that you are
finished composing the mail message.
------oOo------
Silicon Graphics provides a comprehensive customer World Wide Web site.
This site is located at http://www.sgi.com/Support/security/security.html.
------oOo------
For reporting *NEW* SGI security issues, email can be sent to
security-alert@sgi.com or contact your SGI support provider. A
support contract is not required for submitting a security report.
______________________________________________________________________________
This information is provided freely to all interested parties and may
be redistributed provided that it is not altered in any way, Silicon
Graphics is appropriately credited and the document retains and
includes its valid PGP signature.
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