Date: 02 April 2001
References: ESB-2001.375
Click here for printable version
Click here for PGP verifiable version
-----BEGIN PGP SIGNED MESSAGE-----
===========================================================================
AUSCERT External Security Bulletin Redistribution
ESB-2001.132 -- CERT Advisory CA-2001-05
Exploitation of snmpXdmid
2 April 2001
===========================================================================
AusCERT Security Bulletin Summary
---------------------------------
Product: snmpXdmid
Vendor: Sun Microsystems
Operating System: Solaris 2.6
Solaris 7
Solaris 8
Impact: Root Compromise
Access Required: Remote
Ref: AL-2001.06
- --------------------------BEGIN INCLUDED TEXT--------------------
- -----BEGIN PGP SIGNED MESSAGE-----
CERT Advisory CA-2001-05 Exploitation of snmpXdmid
Original release date: March 30, 2001
Source: CERT/CC
A complete revision history can be found at the end of this file.
Systems Affected
Any machine running Solaris 2.6, 7, or 8 with snmpXdmid installed and
enabled. snmpXdmid is installed and enabled by default on these
systems.
Overview
The CERT/CC has received numerous reports indicating that a
vulnerability in snmpXdmid is being actively exploited. Exploitation
of this vulnerability allows an intruder to gain privileged (root)
access to the system.
I. Description
The SNMP to DMI mapper daemon (snmpXdmid) translates Simple Network
Management Protocol (SNMP) events to Desktop Management Interface
(DMI) indications and vice-versa. Both protocols serve a similar
purpose, and the translation daemon allows users to manage devices
using either protocol. The snmpXdmi daemon registers itself with the
snmpdx and dmid daemons, translating and forwarding requests from one
daemon to the other.
snmpXdmid contains a buffer overflow in the code for translating DMI
indications to SNMP events. This buffer overflow is exploitable by
local or remote intruders to gain root privileges.
More information about this vulnerability can be found in
CERT/CC Vulnerability Note VU#648304
Sun Solaris DMI to SNMP mapper daemon snmpXdmid contains buffer overflow
http://www.kb.cert.org/vuls/id/648304
Affected sites have reported discovering the following things on
compromised systems:
* Evidence of extensive scanning for RPC services (port
111/{udp,tcp}) with explicit requests for the snmpXdmid service
port prior to the exploit attempt
* A core file from snmpXdmid on the / partition
* An additional copy of inetd running (possibly using /tmp/bob as a
configuration file)
* A root-privileged telnet backdoor installed and listening on port
2766 (although any port could be used)
* An SSH backdoor installed and listening on port 47018 (although
any port could be used)
* An IRC proxy installed as /var/lp/lpacct/lpacct and listening on
port 6668
* A sniffer installed as /usr/lib/lpset
* Logs altered to hide evidence of the compromise
* System binaries replaced by a rootkit installed in /dev/pts/01/
and /dev/pts/01/bin (the versions of 'ls' and 'find' installed
by the rootkit do not show these directories)
The contents of /dev/pts/01 may include
+ bin
+ crypt
+ idsol
+ patcher
+ su-backup
+ utime
+ bnclp
+ idrun
+ l3
+ pg
+ urklogin
The contents of /dev/pts/01/bin may include
+ du
+ find
+ ls
+ netstat
+ passwd
+ ping
+ psr
+ sparcv7
+ su
Note: Since 'ps' and 'netstat' are both replaced by the rootkit, they
will not show these processes or open ports. However, you may find
that '/usr/ucb/ps' is still intact, and will show the additional
processes.
II. Impact
A local or remote user that is able to send packets to the snmpXdmi
daemon on a system may gain root privileges.
III. Solution
* Apply a patch from Sun when it is available
Sun has been notified of this issue and is actively working on
patches to address the problem. This advisory will be updated when
patches are available.
* Disable snmpXdmi
Until patches are available, sites that do not use both SNMP and
DMI are stongly encouraged to disable snmpXdmid.
One way to accomplish this is to issue the following commands (as
root):
1. Prevent the daemon from starting up upon reboot
mv /etc/rc3.d/SXXdmi /etc/rc3.d/KXXdmi
2. Killing the currently running daemon
/etc/init.d/init.dmi stop`
3. Verify that the daemon is no longer active
ps -ef | grep dmi
4. As an additional measure, you may wish to make the daemon
non-executable
chmod 000 /usr/lib/dmi/snmpXdmid
* Restrict access to snmpXdmi and other RPC services
For sites that require the functionality of snmpXdmi or other RPC
services, local IP filtering rules that prevent hosts other than
localhost from connecting to the daemon may mitigate the risks
associated with running the daemon. Sun RPC services are advertised on
port 111/{tcp,udp}. The snmpXdmid RPC service id is 100249; use
'rpcinfo -p' to list local site port bindings:
# rpcinfo -p | grep 100249
100249 1 udp 32785
100249 1 tcp 32786
Note that site-specific port binding will vary.
Appendix A. - Vendor Information
Sun Microsystems
We can confirm that this affects all versions of Solaris that ship the
SNMP to DMI mapper daemon, that is, Solaris 2.6, 7 and 8. To the best
of my understanding from discussion with the engineering group working
on this, for sites which do use DMI (dmispd) and the mapper
(snmpXdmid), there are no workarounds.
______________________________________________________________________
The CERT/CC thanks Job de Haas (job@itsx.com) of ITSX BV Amsterdam,
The Netherlands (http://www.itsx.com) for reporting this vulnerability
to the CERT/CC.
______________________________________________________________________
This document was written by Brian B. King with significant
contributions by Jeff Havrilla, and Cory F. Cohen.
______________________________________________________________________
This document is available from:
http://www.cert.org/advisories/CA-2001-05.html
______________________________________________________________________
CERT/CC Contact Information
Email: cert@cert.org
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 subscribe to the CERT mailing list for advisories and bulletins,
send email to majordomo@cert.org. Please include in the body of your
message
subscribe cert-advisory
* "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 expressed or
implied as to any matter including, but not limited to, warranty of
fitness for a particular purpose or merchantability, exclusivity or
results obtained from use of the material. Carnegie Mellon University
does not make any warranty of any kind with respect to freedom from
patent, trademark, or copyright infringement.
_________________________________________________________________
Conditions for use, disclaimers, and sponsorship information
Copyright 2001 Carnegie Mellon University.
Revision History
March 30, 2001: Initial release
- -----BEGIN PGP SIGNATURE-----
Version: PGPfreeware 5.0i for non-commercial use
Charset: noconv
iQCVAwUBOsT85wYcfu8gsZJZAQE+jAP+NzhcGlYONhR3O62XsiK5r0pgvCTV8ka8
3SCaNE4BsIbdjIOmcyjsqa3EF8FSpb4XM4B9ttN0SorHaHua/9f74+I0ElR4s3XI
njCOlVFQA8bhAeITiUmsE7jX7qkRZC/cNPzDMgSrEIZROxW5MctT6V9F3QHJ16pj
wW5aPw2rHck=
=t6h8
- -----END PGP SIGNATURE-----
- --------------------------END INCLUDED TEXT--------------------
This security bulletin is provided as a service to AusCERT's members. As
AusCERT did not write the document quoted above, AusCERT has had no control
over its content. The decision to use any or all of this information is
the responsibility of each user or organisation, and should be done so in
accordance with site policies and procedures.
NOTE: This is only the original release of the security bulletin. It may
not be updated when updates to the original are made. If downloading at
a later date, it is recommended that the bulletin is retrieved directly
from the original authors to ensure that the information is still current.
Contact information for the authors of the original document is included
in the Security Bulletin above. If you have any questions or need further
information, please contact them directly.
Previous advisories and external security bulletins can be retrieved from:
http://www.auscert.org.au/Information/advisories.html
If you believe that your system has been compromised, contact AusCERT or
your representative in FIRST (Forum of Incident Response and Security
Teams).
Internet Email: auscert@auscert.org.au
Facsimile: (07) 3365 7031
Telephone: (07) 3365 4417 (International: +61 7 3365 4417)
AusCERT personnel answer during Queensland business hours
which are GMT+10:00 (AEST).
On call after hours for emergencies.
-----BEGIN PGP SIGNATURE-----
Version: 2.6.3i
Charset: noconv
Comment: ftp://ftp.auscert.org.au/pub/auscert/AUSCERT_PGP.key
iQCVAwUBOshf+Ch9+71yA2DNAQGZZgP6A+npY3Uh+iXP/T4urwZmHiD2Y3sSVYMG
U95zixpC0RxKf/bVCYSE9daE+Oprp/UAHDVX7zq7kcHI19qSRG47EbSbDMHMgccX
WeWlRZrFmCzJg30Jayc8lTKw0F2ffQ8aLRBMG11LX/TVSMu057+9WD9QnzhyaBdj
fvlpPbGty6o=
=JM44
-----END PGP SIGNATURE-----
|