Search

The article discusses the concerns among some security experts that denial-of-service (DoS) attacks could be launched against core routers and switches which were raised upon the disclosure in April 2004 of two serious flaws in widely used Internet technologies. One of the vulnerabilities involves Cisco Systems' implementation of the Simple Network Management Protocol in its Internetworking Operating System. The flaw could allow remote attackers to cause vulnerable systems to repeatedly restart when processing specific SNMP requests, eventually leading to DoS conditions. According to Amit Yoran, director of the U.S. Department of Homeland Security's National Cyber Security Division, the flaw is particularly dangerous because it affects a wide range of Cisco's routers and switches and is very easy to exploit. Meanwhile, a US-CERT advisory warned of a critical flaw in the Internet's core Transmission Control Protocol (TCP). The flaw allows remote attackers to create DoS conditions against TCP connections, with sustained attacks capable of disrupting portions of the Internet, the advisory stated. The flaw was disclosed by Great Britain's National Infrastructure Security Co-ordination Centre and involved a long-known weakness in TCP that allows attackers to constantly reset routers by guessing a unique 32-bit number needed for the process.

The article reports that Cisco Systems Inc. has issued a security advisory over the potential vulnerabilities in using OpenSSL open source data encryption software with some of its products. The OpenSSL project advised users of potential problems in October 2005 and Cisco has now confirmed which products are affected and when remedies will be available. Users of most affected products will not be fully protected when using OpenSSL until spring 2006. The flaws in Cisco's products potentially allow remote attackers to capture data and execute arbitrary code on users' systems. OpenSSL is an open source version of Secure Sockets Layer, which is used by browsers to protect data transmitted over the Internet. Cisco said six of its products were affected, ranging from network management systems to wireless controllers.