IRIX tcpmux Port Scanning and Root Compromises

[agent99 () BOYTOY CSD SGI COM (SGI Security Coordinator)]

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______________________________________________________________________________
                Silicon Graphics Inc. Security Advisory

        Title:   tcpmux Port Scanning and Root Compromises
        Number:  19980503-01-I
        Date:    May 28, 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.
______________________________________________________________________________


Silicon Graphics has been in communication with the CERT Coordination
Center in regards to observed increases in tcpmux/port 1 scanning and
root compromises on IRIX based systems.

Upon examining this trend, Silicon Graphics and the CERT Coordination
Center have theorized that a new methodology is currently being used
to identify the continually increasing number of Silicon Graphics IRIX
based systems on the Internet, in order to then target them for potential
attack and compromise.


- -----------------------
- --- Issue Specifics ---
- -----------------------

Silicon Graphics believes at this time that no new IRIX vulnerability has
been found.  However, this new methodology is based upon an understanding
of the default IRIX environment and could lead to a system compromise.

The tcpmux protocol is used by many computing platforms.   By default,
Silicon Graphics based IRIX systems have the tcpmux protocol activated
for use on port 1.  Utilizing this fact, widespread scanning of networks
for systems that respond to probes of port 1 could be used to obtain a
list of systems that might be running IRIX.  Again, at this time, there
is no known vulnerability in the tcpmux protocol or the services it
provides and responding to a probe of port 1 is normal behavior for
the tcpmux protocol.

Using a scan generated list, the next component of the methodology would
be to attempt to exploit IRIX-specific security problems.  This may include
attempting to log into well known accounts that are unpassworded by default
and upon successfully finding any open default account, attempting security
exploits requiring local account access.   These accounts are shipped
unpassworded
by default to foster a "collaborative" environment and are documented in SGI
system documentation and also in SGI security advisory 19951002.

Additionally, the scan generated list could be used to target systems for
remote exploits, which do not require local account access.

In both local and remote cases, a system compromise is possible if security
patches have not been installed and/or the system is misconfigured.



- ----------------
- --- Solution ---
- ----------------

At this time, Silicon Graphics does not believe any new vulnerability
exists in regards to this issue and therefore has no patches to offer.
All current security patches and information can be found at:

      http://www.sgi.com/Support/security/security.html
      ftp://sgigate.sgi.com/patches
      ftp://sgigate.sgi.com/security


Silicon Graphics believes the best measures for preventing exposure
to this new methodology is to 1) ensure all accounts have good passwords
or are disabled, and 2) that all current security patches are installed.

Furthermore, keeping current with new security information and system
monitoring for intrusions would be considered prudent.

If your IRIX machine currently has unpassworded accounts, it would
be prudent to inspect your system for signs of intrusion.  Please
refer to the "Recovering from an Incident" section at the CERT
Coordination Center website (www.cert.org).


- ------------------------
- --- Acknowledgments ---
- ------------------------

Silicon Graphics wishes to thank the CERT Coordination Center 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------

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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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                      ------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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