Protect yourself against future threats.
-----BEGIN PGP SIGNED MESSAGE-----
===========================================================================
AUSCERT External Security Bulletin Redistribution
ESB-2003.0529 -- Cisco Security Notice
Data Leak in UDP Echo Service
01 August 2003
===========================================================================
AusCERT Security Bulletin Summary
---------------------------------
Product: IOS
Publisher: Cisco Systems
Impact: Access Privileged Data
Access Required: Remote
- --------------------------BEGIN INCLUDED TEXT--------------------
- -----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
Data Leak in UDP Echo Service
Revision 1.0
Description
===========
If the udp-small-servers command is enabled, a Cisco IOS® software device may
reply to malformed udp echo packets with some of the contents stored in a
router's memory. By repeatedly sending malformed udp echo packets and capturing
the replies, an attacker can obtain portions of the data that is stored in a
router's memory.
Workarounds are available to mitigate the effects.
Fixed Software
==============
This vulnerability has been fixed by the Cisco Bug ID CSCdk77834. Below are the
first Cisco IOS software releases that are not affected by this vulnerability:
* 12.0(3.2)
* 12.0(3.3)S
* 12.0(3.4)T
* 12.0(3.6)W5(9.0.5)
12.1, 12.2, and 12.3-based images are not affected.
Workaround
==========
The workaround is to disable udp-small-services. The syntax for this command on
routers and switches running Cisco IOS software is as follows:
no service udp-small-servers
The udp-small-servers command is disabled by default since Cisco IOS Software
Release 11.2(1).
It is always recommended to disable unnecessary services on routers and
switches. Refer to Improving Security on Cisco Routers
(http://www.cisco.com/warp/public/707/21.html#possibly_unnecessary) for more
information on improving router security.
- -----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.1 (GNU/Linux)
iD8DBQE/KZn9ezGozzK2tZARAm88AKDDEOepms5pWBGS8+O2GSbJiBVWJwCgt1yh
4uQb39onkchAFo7TiLWfgdw=
=P/VN
- -----END PGP SIGNATURE-----
- --------------------------END INCLUDED TEXT--------------------
You have received this e-mail bulletin as a result of your organisation's
registration with AusCERT. The mailing list you are subscribed to is
maintained within your organisation, so if you do not wish to continue
receiving these bulletins you should contact your local IT manager. If
you do not know who that is, please send an email to auscert@auscert.org.au
and we will forward your request to the appropriate person.
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 follow or act on information or advice
contained in this security bulletin is the responsibility of each user or
organisation, and should be considered in accordance with your organisation's
site policies and procedures. AusCERT takes no responsibility for consequences
which may arise from following or acting on information or advice contained in
this security bulletin.
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 author's website 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/render.html?cid=1980
If you believe that your computer system has been compromised or attacked in
any way, we encourage you to let us know by completing the secure National IT
Incident Reporting Form at:
http://www.auscert.org.au/render.html?it=3192
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 member emergencies only.
-----BEGIN PGP SIGNATURE-----
Comment: http://www.auscert.org.au/render.html?it=1967
iQCVAwUBPynltCh9+71yA2DNAQFhDAP+NIf02/dCn7Y9Mdc2Gd6lim6K4InzAR6T
77CmMsYY4QOzduU2oJD3ckIvhABGy8GwDIDQ3GZ3lP5v+QVvb9UB5pQfODHNE081
RPjNyd5gzVxiKPCNuUni5ljcuerpLur3Wtge+ytnROfdjyZqrK4mQLcv5Bwp8wdO
DOjX2WRmpAs=
=mfnv
-----END PGP SIGNATURE-----