Cisco patches six security flaws that posed DoS cyber attack risk

Cisco has plugged six flaws in its Internetwork Operating System (IOS) Software that could theoretically be exploited by hackers to launch cyber attacks on its customers.
Cisco released the fixes in its IOS Software Security Advisory Bundled Publication. The update features five fixes for its IOS Software and a single patch for its Cisco 7600 Series Route Switch Processor 720 with 10 Gigabit Ethernet uplinks. The advisory said the vulnerabilities are serious as they could be used to mount denial-of-service (DoS) attacks on Cisco customers.
"Exploits of the individual vulnerabilities could result in a DoS condition. Use the Cisco IOS Software Checker to quickly determine if a given Cisco IOS Software release is exposed to Cisco product vulnerabilities," read the advisory.
Although there is no evidence that the vulnerabilities are being exploited, the flaws in Cisco's IOS are very serious. IOS is a widely used network infrastructure: Cisco lists the software as "operating on millions of active systems, ranging from the small home office router to the core systems of the world's largest service provider networks," and claims it "is the most widely leveraged network infrastructure software in the world".
This means a successful DoS attack could cause untold harm to IOS users' systems and customers. DoS attacks are a growing issue facing businesses of all sizes. The attacks work by saturating the victim's machine with external communications requests to the point that they become unresponsive.
The attack strategy has traditionally been used by hacktivists, though other groups have begun experimenting with it. Leaked PRISM documents proved a secret spy unit linked to the UK Government Communications Headquarters (GCHQ) had mounted DoS attacks against the Anonymous collective earlier in February.