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AUSCERT External Security Bulletin Redistribution
ESB-2015.1175
Cisco IOS Software and Cisco IOS XE Software Crafted DHCPv6
Sequence Denial of Service Vulnerability
29 April 2015
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AusCERT Security Bulletin Summary
---------------------------------
Product: Cisco IOS Software
Cisco IOS XE Software
Publisher: Cisco Systems
Operating System: Cisco
Impact/Access: Denial of Service -- Remote/Unauthenticated
Resolution: Patch/Upgrade
CVE Names: CVE-2015-0708
Original Bulletin:
http://tools.cisco.com/security/center/viewAlert.x?alertId=38543
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Vulnerability Alert
Cisco IOS Software and Cisco IOS XE Software Crafted DHCPv6 Sequence Denial of
Service Vulnerability
Threat Type: CWE-399: Resource Management Errors
IntelliShield ID: 38543
Version: 1
First Published: 2015 April 28 15:13 GMT
Last Published: 2015 April 28 15:13 GMT
Port: Not available
CVE: CVE-2015-0708
Urgency: Unlikely Use
Credibility: Confirmed
Severity: Mild Damage
CVSS Base: 6.1
CVSS Version 2.0
CVSS Temporal: 5.0
Version Summary: Cisco IOS Software and Cisco IOS XE Software contain a
vulnerability that could allow an unauthenticated, adjacent attacker to cause
a denial of service condition. Updates are available.
Description
A vulnerability in Cisco IOS Software and Cisco IOS XE Software could allow an
unauthenticated, adjacent attacker to cause a denial of service (DoS)
condition.
The vulnerability is due to improper handling of DHCPv6 packets for a SOLICIT
message for an Identity Association for Non-Temporary Addresses (IA-NA) by a
device running the affected software. An unauthenticated, adjacent attacker
could exploit this vulnerability by sending a crafted sequence exchange of
DHCPv6 packets for a SOLICIT message for an IA-NA to an affected device. If
successful, the attacker could cause the device to crash, resulting in a DoS
condition.
Cisco has confirmed the vulnerability and released software updates.
Warning Indicators
Cisco IOS Software and Cisco IOS XE Software are affected.
IntelliShield Analysis
To exploit this vulnerability, an attacker must be on the same broadcast or
collision domain as the affected device. This access requirement decreases the
likelihood of a successful exploit.
An attacker may need to obtain additional information about the device such as
whether the device is configured with DHCPv6 server. The device must be
configured for DHCPv6 server in order to exploit this vulnerability.
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 CSCur29956 for registered users that 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 crash, resulting in a DoS condition.
Technical Information
The vulnerability is due to improper handling of DHCPv6 packets for a SOLICIT
message for an IA-NA by a device running the affected software when configured
with DHCPv6 server.
An unauthenticated, adjacent attacker could exploit this vulnerability by
sending a crafted sequence exchange of DHCPv6 packets for a SOLICIT message
for an IA-NA to an affected device. If successful, the attacker could cause
the device to crash, 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 allow only privileged users to access
administration or management systems.
Administrators are advised to monitor network traffic for security-related
network activity. Cisco NetFlow can identify such activity. For more
information about Cisco NetFlow, see Introduction to Cisco IOS NetFlow - A
Technical Overview.
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 15.4S 15.4(3)S, 15.4(3)S1 | 15.4SN 15.4(3)SN1 | 15.5S 15.5(1)S
Cisco Cisco IOS XE Software 3.13S .0, .1 | 3.14S .0
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.
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