Vendors sharpen tools to thwart DoS attacks

A new breed of security products designed to mitigate the risk of denial of service (DoS) attacks is coming to market.

Earlier this week, Top Layer Networks announced the general availability of its Attack Mitigator appliance, which gives an added layer of protection that is more effective than traditional firewalls at stopping DoS, DDoS and worm attacks in their tracks.

Based on the ASIC architecture of Top Layer's multi-functional AppSwitch/AppSafe product line, Attack Mitigator ships pre-configured to recognise and effectively block the 15 most common DoS attack mechanisms. Software updates allow the device to guard against the spread of emerging threats, such as Nimda-style attacks.

The device, which would normally sit in front or corporate firewalls, is designed to block attacks through a combination of filters, content inspection and rate limiting features.

Attack Mitigator comes in two flavours: one which support up to eight 10/100Mbps connected and another, more expensive, gigabit connected device. Prices start at $10,000.

Paul Lawrence, director of sales engineering at Top Layer, said the company was targeting the legacy software firewall market with the product, which he said provides some degree of attack mitigation for firms deferring "forklift upgrades" to more secure hardware firewalls. He was careful to note that no security device can give complete protection from denial of service attacks, which are notoriously difficult to prevent.

"Attack Mitigator can't provide absolute protection but it can prevent attacks, such as SYNFlood, that firewalls were not designed to prevent," Lawrence told us. "The product is certainly not a panacea but can reduce the exposure of companies to high-level DoS attacks that even a properly configured network, with routers and firewalls set up properly, can still be susceptible to."

The shortcomings of firewalls, particularly in preventing DoS attacks, are well known to security experts and vendors are coming up with a variety of approaches to deal with the problem.

Firms like Arbor Networks, which has the financial backing of Cisco Systems behind it, are designing products that reconfigure switches and routers in response to network-based denial of service attacks, an approach best suited to the core of service provider networks. Israeli-based WanWall (which launched in Europe this month and has being backed by Intel Capital) is marketing software that sits at the core of service provider networks and filters out denial of service attacks, preventing malicious traffic reaching targeted sites.

Tools which check in-line content or provide central monitoring are also coming to market. Top Layer is competing in this space against firms like Mazu Networks.

Mazu offers an anomaly-based security solution, which Lawrence argued carried a high performance overhead compared to Top Layer's hardware-based approach. Doubtless Mazu would argue its software is more flexible.

The market for tools that prevent against network-based denial of service attacks is still in its infancy but is already becoming a segment to watch, with growth fuelled on the back of concern about the continuing prevalence of such attacks. ®

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