Cisco Network Foundation Protection (NFP) is an umbrella strategy encompassing Cisco IOS Security features that provides the tools, technologies, and services that enable organizations to secure their network foundations. NFP helps to establish a methodical approach to protecting router planes, forming the foundation for continuous service delivery.
The router is typically segmented into three planes of [...]

Reported to Cisco by National Australia Bank’s Security Assurance team, on July 15, 2009 the PSIRT has published a new security advisory concerning to vulnerabilities in Unified Contact Center Express Administration Pages.
Cisco Unified Contact Center Express (Cisco Unified CCX) server contains both a directory traversal vulnerability and a script injection vulnerability in the administration pages [...]

On June 24, 2009, the The Cisco Product Security Incident Response Team (PSIRT) has published 2 new vulnerability advisories.
1) Cisco Physical Access Gateway Denial of Service Vulnerability
A denial of service (DoS) vulnerability exists in the Cisco Physical Access Gateway. There are no workarounds available to mitigate the vulnerability. This vulnerability has been corrected in Cisco [...]

CiscoWorks Common Services contains a vulnerability that could allow an unauthenticated remote attacker to access application and host operating system files.
Cisco has released free software updates that address this vulnerability. A workaround that mitigates this vulnerability is available.
Vulnerable Products
Products that have TFTP services enabled and that run CiscoWorks Common Services versions 3.0.x, 3.1.x, and 3.2.x [...]

Multiple vulnerabilities exist in the Cisco ASA 5500 Series Adaptive Security Appliances and Cisco PIX Security Appliances.
Vulnerable Products
The following is a list of the products affected by each vulnerability as described in detail within this advisory.
VPN Authentication Bypass Vulnerability
Cisco ASA or Cisco PIX security appliances that are configured for IPsec or SSL-based remote access VPN [...]

On March 25, 2009, the The Cisco Product Security Incident Response Team (PSIRT) has published 8 new vulnerability advisories. Mainly these vulnerabilities are DOS attack.
 
1) Cisco IOS cTCP Denial of Service Vulnerability
A series of TCP packets may cause a denial of service (DoS) condition on Cisco IOS devices that are configured as Easy VPN servers [...]

On 4 March 2009 and on 11 March 2009, Cisco has published two new security advisories, which can be exploited by malicious people to conduct a DOS attack or a Remote control attack.
1) Cisco 7600 Series Router Session Border Controller Denial of Service Vulnerability
A denial of service (DoS) vulnerability exists in the Cisco Session Border Controller (SBC) for [...]

The spanning-tree protocol is used to cut loops that redundant links create in bridge networks. These packets are not attested by the system, so an attacker could spoof the BPDU and compromise the network stability!
See below to understand BPDU attack:
In this example the Ciscozine1 switch is elected Root Bridge due to the lower MAC-address (suppose that [...]

On 25 February 2009, Cisco has published three new security advisories, which can be exploited by malicious people to conduct a DOS attack or a Remote control attack.
1) Multiple Vulnerabilities in the Cisco ACE Application Control Engine Module and Cisco ACE 4710 Application Control Engine
The Cisco ACE Application Control Engine Module and Cisco ACE 4710 Application [...]

On February 16th, SuproNet, a local Czech provider, single-handedly caused a global Internet meltdown for upwards of an hour today. SuproNet accomplished this feat by sending out a rather unusual routing update, one which a lot of routers did not handle very well. The result was Internet bedlam.
“What we think happened next is the Internet [...]