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Cisco IOS Gigabit Switch Router PIM Packet Processing Denial of Service Vulnerability

 
Vulnerability AlertPowered by Cisco Security IntelliShield Alert Manager

Threat Type:Unintended Weakness: Denial of Service
IntelliShield ID:16638
Version:1
First Published:September 24, 2008 03:25 PM EDT
Last Published:September 24, 2008 03:25 PM EDT
Vector:Network
Authentication:None
Exploit:Functional
Port: Not Available
CVE:CVE-2008-3809
BugTraq ID:31356
 
Urgency: Unlikely Use
Credibility: Confirmed
Severity: Mild Damage
CVSS Base:7.8 CVSS Calculator
CVSS Version 2
CVSS Temporal:6.4
 
Version Summary:

Cisco IOS Gigabit Switch Router contains a vulnerability that could allow an unauthenticated, remote attacker to cause the affected router to crash. Updates are available.

 
 
Description

Cisco IOS Gigabit Switch Router (GSR) devices that are configured for Protocol Independent Multicast (PIM) contain a vulnerability that could allow an unauthenticated, remote attacker to cause the device to crash.

The vulnerability is due to an error that may occur when the devices process crafted PIM packets.  An attacker could exploit the vulnerability by sending a crafted request to the affected system.  An exploit could allow the attacker to cause the GSR device to crash, which may result in a denial of service (DoS) condition.

Cisco has confirmed the vulnerability in a security advisory and released updated versions.

 
Warning Indicators

A complete list of affected Cisco IOS devices is available at the following link: cisco-sa-20080924-multicast

 
IntelliShield Analysis

Limited information is available to describe this vulnerability. A single exploit could allow the attacker to cause the affected router to reload, which may result in a DoS condition. Repeated exploitation could allow an attacker to render a device completely unavailable.

Cisco indicated through CVSS scoring the existence of functional exploit code; however, this exploit code is not known to be publicly available.

 
Vendor Announcements

Cisco has released a security advisory to address Cisco bug ID CSCsl34355 at the following link: cisco-sa-20080924-multicast

 
Impact

An unauthenticated, remote attacker could exploit this vulnerability to cause a GSR device to reload, which may result in a DoS condition. Repeated attacks could render a device completely unavailable.

 
Technical Information

The vulnerability exists when Cisco IOS software that is running on a GSR device is configured to process PIM packets.  PIM is not enabled by default and must be enabled for a system to be vulnerable. Cisco IOS software does not properly process malformed PIM requests.  The processing of a malicious request could cause a device to fail and restart.

An unauthenticated, remote attacker could exploit the vulnerability by crafting a malicious PIM request and sending it to an affected system.  When the packet is processed, the system fails to properly handle the request.  An exploit could allow the attacker to cause the affected router to reload, which may result in a DoS condition.

 
Safeguards

Administrators are advised to apply the appropriate update.

Administrators may consider using access control lists (ACLs) to restrict packets that do not originate from authorized sources.

Administrators may consider allowing only trusted PIM neighbors to access the device.

The Cisco Applied Intelligence team has created the following companion document to guide administrators in identifying and mitigating attempts to exploit this vulnerability prior to applying updated software: cisco-amb-20080924-multicast

 
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 e-mail at tac@cisco.com.


Signatures
 
Cisco Systems Cisco Intrusion Prevention System (IPS) 6.0
6999/0Cisco PIM Multicast Denial of Service AttackS35809/24/2008
 
Alert History
 

Initial Release



Product Sets
 
The security vulnerability applies to the following combinations of products.

Primary Products:
CiscoIOS12.0 Base | 12.0DA Base | 12.0DB Base | 12.0DC Base | 12.0S Base | 12.0SC Base | 12.0SL Base | 12.0SP Base | 12.0ST Base | 12.0SX Base | 12.0SY Base | 12.0SZ Base | 12.0T Base | 12.0W Base | 12.0WC Base | 12.0XA Base | 12.0XB Base | 12.0XC Base | 12.0XD Base | 12.0XE Base | 12.0XG Base | 12.0XH Base | 12.0XI Base | 12.0XJ Base | 12.0XK Base | 12.0XL Base | 12.0XM Base | 12.0XN Base | 12.0XQ Base | 12.0XR Base | 12.0XT Base | 12.0XV Base | 12.1 Base | 12.1AA Base | 12.1AX Base | 12.1AY Base | 12.1CX Base | 12.1DA Base | 12.1DB Base | 12.1DC Base | 12.1E Base | 12.1EA Base | 12.1EB Base | 12.1EC Base | 12.1EO Base | 12.1EU Base | 12.1EW Base | 12.1EX Base | 12.1EY Base | 12.1EZ Base | 12.1GA Base | 12.1GB Base | 12.1T Base | 12.1XA Base | 12.1XB Base | 12.1XC Base | 12.1XD Base | 12.1XE Base | 12.1XF Base | 12.1XG Base | 12.1XH Base | 12.1XI Base | 12.1XJ Base | 12.1XK Base | 12.1XL Base | 12.1XM Base | 12.1XP Base | 12.1XQ Base | 12.1XR Base | 12.1XS Base | 12.1XT Base | 12.1XU Base | 12.1XV Base | 12.1XW Base | 12.1XX Base | 12.1XY Base | 12.1XZ Base | 12.1YA Base | 12.1YB Base | 12.1YC Base | 12.1YD Base | 12.1YE Base | 12.1YF Base | 12.1YH Base | 12.1YI Base | 12.2 Base | 12.2B Base | 12.2BC Base | 12.2BW Base | 12.2BX Base | 12.2BY Base | 12.2BZ Base | 12.2CX Base | 12.2CY Base | 12.2CZ Base | 12.2DA Base | 12.2DD Base | 12.2DX Base | 12.2EW Base | 12.2EWA Base | 12.2EX Base | 12.2EY Base | 12.2EZ Base | 12.2FZ Base | 12.2IXA Base | 12.2IXB Base | 12.2IXC Base | 12.2IXD Base | 12.2MB Base | 12.2MC Base | 12.2S Base | 12.2SB Base | 12.2SBC Base | 12.2SE Base | 12.2SEA Base | 12.2SEB Base | 12.2SEC Base | 12.2SED Base | 12.2SEE Base | 12.2SEG Base | 12.2SG Base | 12.2SGA Base | 12.2SM Base | 12.2SO Base | 12.2SRA Base | 12.2SU Base | 12.2SV Base | 12.2SW Base | 12.2SX Base | 12.2SXA Base | 12.2SXB Base | 12.2SXD Base | 12.2SXE Base | 12.2SXF Base | 12.2SY Base | 12.2SZ Base | 12.2T Base | 12.2tpc Base | 12.2XA Base | 12.2XB Base | 12.2XC Base | 12.2XD Base | 12.2XE Base | 12.2XF Base | 12.2XG Base | 12.2XH Base | 12.2XI Base | 12.2XJ Base | 12.2XK Base | 12.2XL Base | 12.2XM Base | 12.2XN Base | 12.2XQ Base | 12.2XR Base | 12.2XS Base | 12.2XT Base | 12.2XU Base | 12.2XV Base | 12.2XW Base | 12.2YA Base | 12.2YB Base | 12.2YC Base | 12.2YD Base | 12.2YE Base | 12.2YF Base | 12.2YG Base | 12.2YH Base | 12.2YJ Base | 12.2YK Base | 12.2YL Base | 12.2YM Base | 12.2YN Base | 12.2YO Base | 12.2YP Base | 12.2YQ Base | 12.2YR Base | 12.2YT Base | 12.2YU Base | 12.2YV Base | 12.2YW Base | 12.2YX Base | 12.2YY Base | 12.2YZ Base | 12.2ZA Base | 12.2ZB Base | 12.2ZC Base | 12.2ZD Base | 12.2ZE Base | 12.2ZF Base | 12.2ZG Base | 12.2ZH Base | 12.2ZJ Base | 12.2ZL Base | 12.2ZP Base | 12.2ZU Base | 12.2ZX Base | 12.3 Base, T | 12.3B Base | 12.3BC Base | 12.3BW Base | 12.3T Base | 12.3TPC Base | 12.3VA Base | 12.3XA Base | 12.3XB Base | 12.3XC Base | 12.3XD Base | 12.3XE Base | 12.3XF Base | 12.3XG Base | 12.3XI Base | 12.3XJ Base | 12.3XK Base | 12.3XL Base | 12.3XQ Base | 12.3XR Base | 12.3XS Base | 12.3XU Base | 12.3XW Base | 12.3XX Base | 12.3XY Base | 12.3XZ Base | 12.3YA Base | 12.3YD Base | 12.3YF Base | 12.3YG Base | 12.3YH Base | 12.3YI Base | 12.3YJ Base | 12.3YK Base | 12.3YM Base | 12.3YQ Base | 12.3YS Base | 12.3YT Base | 12.3YU Base | 12.3YX Base | 12.3YZ Base | 12.3ZA Base | 12.4 Base | 12.4MR Base | 12.4T Base | 12.4XA Base | 12.4XB Base | 12.4XC Base | 12.4XD Base | 12.4XE Base | 12.4XG Base | 12.4XP Base | 12.4XT Base

Associated Products:
N/A



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