More than one-third of Android apps request "excessive permissions," giving them access to more data than they require.

That finding comes from a study conducted by South Korean antivirus vendor AhnLab, which scanned 178 "best rated" Android applications using its cloud-based Android security scanning service.

All told, of the apps scanned, AhnLab found that 43% requested excessive device information, 39% requested unusual levels of location information, 33% requested excessive access to personal information, and 8% wanted excessive information about service plans.

[ Google's StreetView put data collection above people's security. See Google Wardriving: How Engineering Trumped Privacy. ]

According to HoWoong Lee, director of the AhnLab Security E-Response Center, mobile applications that access excessive amounts of data are a concern because they may have access to banking data and personal emails, or be able to retrieve information that would allow attackers to clone smartphones or sign up mobile subscribers for premium services. Some apps, meanwhile, not only access but also store this sensitive information, oftentimes in unencrypted form. Furthermore, users may not notice any malware that targets sensitive stored information running in the background, surreptitiously siphoning away stored data.

But having legitimate applications access more data than they require would appear to be quite common. That goes not just for legitimate Android apps, as well as malware, but also for iOS apps.

Many social networking applications, including Path and Hipster, were called out earlier this year over revelations that they sent unencrypted copies of iOS users' address books back to their servers. While the developers behind Path defended the practice as a way of helping them connect users who already knew each other, the resulting outcry led the app developer to make the address book sharing "opt in."

Apple likewise weighed in, saying that slurping people's contact information without their permissions would be against its development guidelines. Apple apparently hadn't been testing iOS apps for such behavior as part of its App Store review process.

Not long after, Twitter, Yelp, and Foursquare also came clean, saying that they likewise transmitted users' contact information whenever people selected features with labels such as "find friends." But such information was often stored in unencrypted format, again creating an information security risk.

Apps running on Android or iOS that request, store, or share excessive amounts of information add to already pervasive business concerns over the security of mobile handsets. So, what can be done to address the problem?

One solution for businesses is application whitelisting, which means ensuring that any Android device that wants to connect to the corporate network runs only approved apps. While the practice is controversial, many security experts see it as the best solution for keeping malware and untrusted apps--such as those requesting excessive data access rights--off of Android handsets.

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