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AUSCERT External Security Bulletin Redistribution
ESB-2015.2143
Cisco NX-OS Internet Group Management Protocol Denial of
Service Vulnerability
18 August 2015
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AusCERT Security Bulletin Summary
---------------------------------
Product: Cisco NX-OS Software
Publisher: Cisco Systems
Operating System: Cisco
Impact/Access: Denial of Service -- Remote/Unauthenticated
Resolution: Patch/Upgrade
CVE Names: CVE-2015-4324
Original Bulletin:
http://tools.cisco.com/security/center/viewAlert.x?alertId=40470
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Vulnerability Alert
Cisco NX-OS Internet Group Management Protocol Denial of Service Vulnerability
Threat Type: CWE-119: Buffer Errors
IntelliShield ID: 40470
Version: 1
First Published: 2015 August 17 14:34 GMT
Last Published: 2015 August 17 14:34 GMT
Port: Not available
CVE: CVE-2015-4324
Urgency: Unlikely Use
Credibility: Confirmed
Severity: Mild Damage
CVSS Base: 6.1
CVSS Version 2.0
CVSS Temporal: 5.0
Version Summary: Cisco NX-OS Internet Group Management Protocol 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 Internet Group Management Protocol version 3 (IGMPv3)
input packet processing of Cisco NX-OS could allow an unauthenticated,
adjacent attacker to cause the IGMP process to restart due to a malformed IGMP
packet, which could cause a denial of service (DoS) condition on the device.
The vulnerability is due to improper input validation when ensuring the memory
allocated is large enough for the number of included sources in the IGMPv3
packet. An attacker could exploit this vulnerability by sending a crafted
IGMPv3 packet to the targeted device. An exploit could allow the attacker to
cause the IGMP process to restart due to a buffer overflow, which may cause a
DoS condition.
Cisco has confirmed the vulnerability. Software updates are available.
Warning Indicators
Cisco NX-OS Software is vulnerable.
IntelliShield Analysis
An unauthenticated, adjacent attacker could use this vulnerability if the
targeted device's IGMPv3 snooping is configured on one or more VLANs and
running the affected version of the software.
To exploit this vulnerability, an attacker must be on the same broadcast or
collision domain as the affected device. This access requirement could
decrease the likelihood of a successful exploit.
Vendor Announcements
Cisco has released bug IDs CSCuv69713, CSCuv69717, CSCuv69723, CSCuv69732, and
CSCuv48908 for registered users, which contain additional details and
up-to-date lists of affected product versions.
Impact
An unauthenticated, adjacent attacker could exploit this vulnerability to
cause the targeted device to become unavailable because of a DoS condition.
Technical Information
The vulnerability is due to improper input validation when ensuring that the
memory allocated is large enough for the number of included sources in the
IGMPv3 packet.
An unauthenticated, adjacent attacker could exploit this vulnerability by
sending a crafted IGMPv3 packet to the targeted device. An exploit could allow
the attacker to cause the IGMP process to restart due to a buffer overflow,
which could cause a DoS condition on the device. If the malformed packet is
continuously sent to the targeted device, the DoS condition will remain and
the device will continue to be unavailable.
Safeguards
Administrators are advised to apply the appropriate updates.
Administrators are advised to allow only trusted users to access local
systems.
Administrators are advised to monitor affected systems.
Administrators may consider using IP-based access control lists (ACLs) to
allow only trusted systems to access the affected systems.
Administrators are advised to remove the IGMPv3 snooping configuration.
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 Cisco NX-OS Software Cisco Nexus 1000V Switch for VMware vSphere
7.3(0)ZN(0.81) | for Nexus 3000 Series 7.3(0)ZN(0.81) | for Nexus 4000 Series
4.1(2)E1(1c) | for Nexus 7000 Series 7.2(0)N1(0.1) | for Nexus 9000 Series
7.3(0)ZN(0.81)
Associated Products:
N/A
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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