Date: Tue, 23 Feb 1999 17:18:28 -0500
From: CERT Advisory <[email protected]>
To: [email protected]Subject: CERT Summary CS-99.01
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CERT Summary CS-99-01
February 23, 1999
The CERT Coordination Center periodically issues the CERT summary to
draw attention to the types of attacks currently being reported to our
incident response team, as well as to other noteworthy incident and
vulnerability information. The summary includes pointers to sources of
information for dealing with the problems.
Past CERT summaries are available from
http://www.cert.org/summaries/
______________________________________________________________________
Recent Activity
Since the last CERT summary, issued in December 1998 (CS-98.08), we
have seen these trends in incidents reported to us.
1. Widespread Scans
We continue to receive numerous daily reports of intruders using
tools to scan networks for multiple vulnerabilities. Intruder
scanning tools continue to become more sophisticated.
On January 28, 1999, we published an incident note describing a
new scanning tool that searches for multiple known vulnerabilities
on remote systems. The tool incorporates probes for known
vulnerabilities, remote operating system identification, and a
scripting language that simplifies automation of probes and
exploitation attempts. For more information, see our incident note
at
http://www.cert.org/incident_notes/IN-99-01.html
Reports also indicate that scanning techniques addressed in
previous CERT incident notes, such as scripted tools and stealth
scanning, are still being employed by intruders. For more
information, see
+ http://www.cert.org/incident_notes/IN-98-06.html
+ http://www.cert.org/incident_notes/IN-98-05.html
+ http://www.cert.org/incident_notes/IN-98.04.html
+ http://www.cert.org/incident_notes/IN-98.02.html
The daily reports of widespread scans and exploitation attempts
involve many vulnerabilities; however, the most frequent reports
involve activity with well-known vulnerabilities in "mountd",
"imap", and "pop3" services for which CERT advisories have been
published. These services are installed and enabled by default in
some operating systems. The scans and exploitation attempts still
result in sites being compromised. See the following advisories
for more information:
+ sunrpc (tcp port 111) and mountd (635)
http://www.cert.org/advisories/CA-98.12.mountd.html
+ imap (tcp port 143)
http://www.cert.org/advisories/CA-98.09.imapd.html
+ pop3 (tcp port 110)
http://www.cert.org/advisories/CA-98.08.qpopper_vul.html
We encourage you to make sure that all systems at your site are up
to date with patches and that your machines are properly secured.
2. Back Orifice and NetBus
We continue to receive daily reports of incidents involving
Windows-based "remote administration" programs such as Back Orifice and
NetBus. Occasionally these are reports of compromised machines that
have one of these tools installed. However, the majority of these
reports involve sites that have detected intruders scanning for the
presence of these tools. These scans may appear as unauthorized traffic
as follows:
+ NetBus - connection requests (SYN) packets to TCP ports
12345, 12346, or 20034
+ Back Orifice - UDP packets to port 31337
Keep in mind that these tools can be configured to listen on
different ports. Because of this, we encourage you to investigate
any unexplained network traffic.
For more information about Back Orifice, review CERT vulnerability
note VN-98.07:
http://www.cert.org/vul_notes/VN-98.07.backorifice.html
3. Trojan Horse Programs
Over the past few months, we have seen an increase in the number
of incident reports related to Trojan horse programs affecting
both Windows and UNIX platforms.
+ CERT advisory CA-99-02 includes descriptions of several
recent incidents involving Trojan horse programs, including a
false upgrade to Internet Explorer, a Trojan horse version of
TCP Wrappers, and a Trojan horse version of util-linux. The
advisory also provides advice for system and network
administrators, end users, software developers, and
distributors. The advisory is available from
http://www.cert.org/advisories/CA-99-02-Trojan-Horses.html
+ CERT advisory CA-99-01, discusses the Trojan horse version of
TCP Wrappers in greater detail, and provides information on
how to verify the integrity of your TCP Wrappers
distribution.
http://www.cert.org/advisories/CA-99-01-Trojan-TCP-Wrappers.html
4. FTP Buffer Overflows
Very recently, we have received a few reports of intruders
scanning for and exploiting a remote buffer overflow vulnerability
in various FTP servers. By supplying carefully designed commands
to the FTP server, intruders can force the server to execute
arbitrary commands with root privilege. Intruders can exploit the
vulnerability remotely to gain administrative access. We encourage
you to review text provided by Netect, Inc. in CERT advisory
CA-99-03, which describes the ftpd vulnerability in more detail.
The advisory is available from
http://www.cert.org/advisories/CA-99-03-FTP-Buffer-Overflows.html
__________________________________________________________________
What's New and Updated
Since the last CERT summary, we have developed new and updated
+ Advisories
+ Incident notes
+ Security improvement modules
+ Technical reports
+ The CERT/CC 1998 Annual Report
+ Computer Security Incident Response Team (CSIRT) Handbook
+ Incident response courses
There are descriptions of these documents and links to them on our
What's New web page at
http://www.cert.org/nav/whatsnew.html
__________________________________________________________________
This document is available from:
http://www.cert.org/summaries/CS-99-01.html.
__________________________________________________________________
CERT/CC Contact Information
Email: [email protected]
Phone: +1 412-268-7090 (24-hour hotline)
Fax: +1 412-268-6989
Postal address:
CERT Coordination Center
Software Engineering Institute
Carnegie Mellon University
Pittsburgh PA 15213-3890
U.S.A.
CERT personnel answer the hotline 08:00-20:00 EST(GMT-5) /
EDT(GMT-4) Monday through Friday; they are on call for emergencies
during other hours, on U.S. holidays, and on weekends.
Using encryption
We strongly urge you to encrypt sensitive information sent by
email. Our public PGP key is available from
http://www.cert.org/CERT_PGP.key. If you prefer to use DES, please call
the CERT hotline for more information.
Getting security information
CERT publications and other security information are available from our
web site http://www.cert.org/. To be added to our mailing list for
advisories and bulletins, send email to [email protected]
and include SUBSCRIBE your-email-address in the subject of your
message.
Copyright 1999 Carnegie Mellon University.
Conditions for use, disclaimers, and sponsorship information can
be found in http://www.cert.org/legal_stuff.html.
* "CERT" and "CERT Coordination Center" are registered in the U.S.
Patent and Trademark Office
__________________________________________________________________
NO WARRANTY
Any material furnished by Carnegie Mellon University and the
Software Engineering Institute is furnished on an "as is" basis.
Carnegie Mellon University makes no warranties of any kind, either
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material. Carnegie Mellon University does not make any warranty of
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