Protect yourself against future threats.
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
===========================================================================
AUSCERT External Security Bulletin Redistribution
ESB-2015.1331
Cisco IOS Voice Gateway Malformed ISDN Q931 Message Denial
of Service Vulnerability
18 May 2015
===========================================================================
AusCERT Security Bulletin Summary
---------------------------------
Product: Cisco IOS Voice Gateway
Publisher: Cisco Systems
Operating System: Cisco
Impact/Access: Denial of Service -- Remote/Unauthenticated
Resolution: Patch/Upgrade
CVE Names: CVE-2015-0731
Original Bulletin:
http://tools.cisco.com/security/center/viewAlert.x?alertId=38833
- --------------------------BEGIN INCLUDED TEXT--------------------
Vulnerability Alert
Cisco IOS Voice Gateway Malformed ISDN Q931 Message Denial of Service
Vulnerability
Threat Type: CWE-399: Resource Management Errors
IntelliShield ID: 38833
Version: 1
First Published: 2015 May 14 15:44 GMT
Last Published: 2015 May 14 15:44 GMT
Port: Not available
CVE: CVE-2015-0731
Urgency: Unlikely Use
Credibility: Confirmed
Severity: Mild Damage
CVSS Base: 6.1
CVSS Temporal: 5.0
Version Summary: Cisco IOS contains a vulnerability that could allow an
unauthenticated, adjacent attacker to cause a denial of service condition.
Updates are available.
Description
A vulnerability in the Integrated Services Digital Network (ISDN) processing
code of Cisco IOS could allow an unauthenticated, adjacent attacker to cause a
reload of the affected device.
The vulnerability is due to improper processing of malformed ISDN Q931 SETUP
messages. An attacker could exploit this vulnerability by sending malformed
Q931 SETUP messages to be processed by a targeted device. An exploit could
allow the attacker to cause the device to reload, resulting in a denial of
service (DoS) condition.
Cisco has confirmed the vulnerability and software updates are available.
Warning Indicators
Cisco IOS is affected.
IntelliShield Analysis
To exploit this vulnerability, an attacker must be on the same broadcast or
collision domain as the targeted device. This access requirement decreases the
likelihood of a successful exploit.
Cisco indicates through the CVSS score that functional exploit code exists;
however, the code is not known to be publicly available.
Vendor Announcements
Cisco has released bug ID CSCut37890 for registered users, which contains
additional details and an up-to-date list of affected product versions.
Impact
An unauthenticated, adjacent attacker could exploit this vulnerability to
cause an affected device to reload, resulting in a DoS condition.
Technical Information
The vulnerability is due to improper processing of malformed ISDN Q931 SETUP
messages by a device running an affected version of Cisco IOS.
An attacker could exploit this vulnerability by sending malformed Q931 SETUP
messages to a targeted device. An exploit could allow the attacker to cause
the device to reload, resulting in a DoS condition.
Safeguards
Administrators are advised to apply the appropriate updates.
Administrators are advised to allow only trusted users to have network access.
Administrators are advised to monitor affected systems.
Patches/Software
Cisco customers with active contracts can obtain updates through the Software
Center at the following link: Cisco. Cisco customers without contracts can
obtain upgrades by contacting the Cisco Technical Assistance Center at
1-800-553-2447 or 1-408-526-7209 or via email at tac@cisco.com.
Alert History
Initial Release
Product Sets
The security vulnerability applies to the following combinations of products.
Primary Products:
Cisco IOS 15.3S 15.3(3)S1
Associated Products:
N/A
Alerts and bulletins on the Cisco Security Intelligence Operations Portal are
highlighted by analysts in the Cisco Threat Operations Center and represent a
subset of the comprehensive content that is available through Cisco Security
IntelliShield Alert Manager Service. This customizable threat and
vulnerability alert service provides security staff with access to timely,
accurate, and credible information about threats and vulnerabilities that may
affect their environment.
LEGAL DISCLAIMER
The urgency and severity ratings of this alert are not tailored to individual
users; users may value alerts differently based upon their network
configurations and circumstances. THE ALERT, AND INFORMATION CONTAINED
THEREIN, ARE PROVIDED ON AN "AS IS" BASIS AND DO NOT IMPLY ANY KIND OF
GUARANTEE OR WARRANTY, INCLUDING THE WARRANTIES OF MERCHANTABILITY OR FITNESS
FOR A PARTICULAR USE. YOUR USE OF THE ALERT, AND INFORMATION CONTAINED
THEREIN, OR MATERIALS LINKED FROM THE ALERT, IS AT YOUR OWN RISK. INFORMATION
IN THIS ALERT AND ANY RELATED COMMUNICATIONS IS BASED ON OUR KNOWLEDGE AT THE
TIME OF PUBLICATION AND IS SUBJECT TO CHANGE WITHOUT NOTICE. CISCO RESERVES
THE RIGHT TO CHANGE OR UPDATE ALERTS AT ANY TIME.
- --------------------------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.
NOTE: Third Party Rights
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
===========================================================================
Australian Computer Emergency Response Team
The University of Queensland
Brisbane
Qld 4072
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
iQIVAwUBVVlEbBLndAQH1ShLAQJ1Uw//cV6VTSj+/+BEVqgxibVrEYMu0Dw1b6oe
cHTzOZG78P0pX7MuPV/jA0iAsX2XEwTAKOgL7sp0uNfN1iu4aimekOYVqVIxsyV2
edBtm78wfxMuJ8st6lJ7Adx9ZxuH9iqd+hdcBb6rlI7iyCI8CbNpmzwNMejGiWKB
JAqvo5IkoW5mtVteNcbjASw/12Y3qogT5F0Fz3nSjtrap4liZA6v3o6NWkBJ1+hS
JgS/l6v1AP+2kh4q3voQw8HqE+GvphIbbhsibOuLohT/N+qcMFKmhSnzDK7LJbvd
hGrFTtaPJ9xEyv9nTdATTUoFU7Nh56rOfj5bZXWgRM3OBxE3GG61GINjuhRQjZH+
Nkb9lQeQzUUe7bYvqcI+GMD/bxWPLNpFGuZFk9LeKdvRDjlYvbNmoKaImS7Tcj8t
HU+REI1RoC/uLnI07POZeze/XeZjnu++ObbvT0yAwD1ACE5u02f0pV1T9V7It0IQ
yvzB0gqIc/9vNnC/kcCvR4V+7PVwhgZjnyiL0fvY8hkvXJ103s0Wa17Wt1dv6hBg
b+ieuoYBBQQH/heKRXxlVCdsyoz0rqOkq9YWng8o8iijeCM3prGNcZW42iYc/nim
SzkTHHSmkZDWV3D8oUKv4CZwGvul6ntzhLsSRr7mqj1omlxmXZwvPMmHg/iyDno5
giQW6IfYTFI=
=N/iJ
-----END PGP SIGNATURE-----