A vulnerability in the Ethernet Connectivity Fault Management (CFM) handling code of Cisco IOS 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 parsing of malformed CFM packets sent to an affected device. An attacker could exploit this vulnerability by sending malformed CFM packets to be processed by an affected device. An exploit could allow the attacker to cause a reload of the affected device.
Cisco has confirmed the vulnerability in a security notice and released software updates.
Indicators of Compromise
At the time this alert was first published, Cisco IOS Software version 12.2(33)SRE9a and prior and Cisco IOS XE Software version 3.13S and prior were vulnerable. Later releases Cisco IOS and Cisco IOS XE Software may also be vulnerable.
The vulnerability is due to improper parsing of malformed CFM packets sent to a device running an affected version of Cisco IOS or Cisco IOS XE Software.
An unauthenticated, adjacent attacker could exploit this vulnerability by sending malformed CFM packets to be processed by an affected device. An exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition.
To exploit this vulnerability, an attacker must be on the same broadcast or collision domain as an affected 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.
Administrators are advised to apply the appropriate updates.
Administrators are advised to allow only trusted users to have network access.
Administrators may consider using IP-based access control lists (ACLs) to allow only trusted systems to access the affected systems.
Administrators are advised to monitor affected systems.
Cisco has released a security notice at the following link: CVE-2014-3409
Customers are advised to consult Cisco bug ID CSCuq93406 for the most complete list of affected product versions.
Cisco customers with active contracts should contact their Cisco support team for assistance in upgrading to a software version that includes fixes for this vulnerability. Cisco customers without contracts may contact the Cisco Technical Assistance Center at 1-800-553-2447 or 1-408-526-7209 or via email at firstname.lastname@example.org for assistance.
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Cisco Multivendor Vulnerability Alerts respond to vulnerabilities identified in third-party vendors' products. These alerts contain information compiled from diverse sources and provide comprehensive technical descriptions, objective analytical assessments, workarounds and practical safeguards, and links to vendor advisories and patches.