Cisco IOS Software TCP Denial-of-service Vulnerability
Number: AV10-032
Date: 13 August 2010
Purpose
The purpose of this advisory is to raise awareness of a TCP denial-of-service (DoS) vulnerability in Cisco IOS Software version 15.1(2)T.
Assessment
A remote user can send specially crafted data during the TCP establishment phase to cause the target TCP connection to remain in a SYNRCVD or SYNSENT state. A remote user can repeat this to consume excessive system resources and prevent new TCP connections. No authentication is required to exploit this vulnerability, and an attacker does not need to complete the three-way handshake. This vulnerability can be exploited using spoofed packets but may also be triggered by normal network traffic. CVSS rating is 7.8, High.
CVE Reference: CVE-2010-2827
Cisco Reference: Cisco bug ID CSCti18193
Cisco has released Cisco IOS Software version 15.1(2)T0a to address this vulnerability.
Affected Products
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This vulnerability affects only Cisco IOS Software version 15.1(2)T.
To determine the version that is running on a Cisco product, administrators can log in to the device and issue the show version command to display the system banner. Directions and details can be found in the Cisco Security Advisory under the Vulnerable Products section.
http://www.cisco.com/warp/public/707/cisco-sa-20100812-tcp.shtml
References
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http://www.cisco.com/warp/public/707/cisco-sa-20100812-tcp.shtml
http://www.cisco.com/en/US/products/products_security_advisory09186a0080b4095e.shtml
Suggested action
CCIRC recommends that organizations liaise with the administrators/maintainers of the affected products to assess exposure and apply vendor-recommended updates and/or workarounds as appropriate.
Note to Readers
The Canadian Cyber Incident Response Centre (CCIRC) provides a focal point for Canada's cyber threat and vulnerability warning, analysis and response. CCIRC is responsible for assuring the resilience of national critical infrastructure through monitoring threats and coordinating a federal response to cyber security incidents of national interest. CCIRC operates in conjunction with the Government Operations Centre (GOC) within Public Safety Canada and is a key component of the government's all-hazards approach to emergency management and national security.
For general information, please contact Public Safety Canada's Public Affairs division at:
Telephone: 613-944-4875 or 1-800-830-3118
Fax: 613-998-9589
E-mail: communications@ps-sp.gc.ca