An increasingly popular cellphone technology has a major security flaw that went undetected for years, CNN Money reported.


The problem exists in some models of what are called femtocells, devices that mobile network operators use to bring wireless service to low-coverage zones. The boxes, typically as small as a standard cable modem, can be used in hard-to-reach spots like the top of an apartment building or a home in the mountains.


Researchers at iSEC Partners discovered the security hole, and found that an attacker could eavesdrop on everything a target did on his or her phone while using the femtocells, also referred to as "network extenders," for coverage. Analysts project there will be as many of 50 million femtocells in use by 2014.


Verizon Wireless, whose network the study focused on, said the problem has now been repaired in all femtocells it is currently using. The holes could still exist in other network providers.


"You do need some level of technical skills, but people are learning those skills in college," said Tom Ritter, iSEC Partners senior security consultant, in an interview with CNN Money.  "Breaking into one of these devices, or a device like this, is within the realm of people working at home."


Click here for a Business Record story on how to protect yourself from hackers.