Wireless networks leave computers open to "drive-by" hacking

2019-03-06 05:15:01

By Will Knight A string of weaknesses with the security infrastructure protecting wireless computer networks have been highlighted by researchers at a major computer security conference in the US. The problems have been identified with the 802.11 set of specifications created by the Institute of Electrical and Electronics Engineers for wireless local area networks. Wireless networks are growing in popularity. However, experts have described ways to eavesdrop on wireless traffic, intercept communications and even gain full access to such a network. “As 802.11 wireless networks become more common, companies’ intranets are increasingly being exposed to drive-by hacking,” said Dave Safford, manager of network security research at IBM. Information on these vulnerabilities was presented on Friday at the Black Hat Conference in Las Vegas. This is the most high-profile US meeting of legitimate computer security experts and underground computer hackers. The wireless specification known as 802.11 is protected with a system called Wired Equivalent Privacy (WEP). Communications are encrypted with a stream cipher, meaning that each bit is altered according to a secretly held key during transmission. There are a number of rules designed to ensure that keys are used securely and no one can eavesdrop on messages. But Ian Goldberg, chief technical officer for Canada’s Zero Knowledge systems, presented fundamental flaws with the implementation of the encrypting rules that leave 802.11 communications vulnerable. He described ways to monitor wireless network traffic in order to gather information about how messages are encrypted. Given this, he says it is possible to modify and even decrypt communications altogether. Another conference delegate built on these vulnerabilities to describe practical methods of attacking 802.11 networks. Tim Newsham, a consultant with US security firm @Stake, outlined a technique for decoding messages by testing out a series of cryptographic keys at high speed. Further research indicates that networks using encryption that cannot be cracked in this way may still be vulnerable to automated password guessing. “WEP is inherently insecure,” Newsham said. “So using WEP is essentially just throwing another barrier in front of the attacker.” Another computer security expert, Mandy Andress of ArcSec Technologies, described how unprotected wireless networks can be attacked in many real situations by roaming hackers. Ollie Whitehouse, a computer security expert with @Stake in the UK says that research in this area is likely to increase investment in wireless security. “There are flaws that require modification and I think you will also see people investing in larger encryption keys and incurring the computational overhead,