According to Appthority's Summer 2013 App Reputation Report, 83 percent of the 400 most popular Android and iOS apps are associated with security risks and privacy issues.

Notably, the report states that iOS apps exhibit more risky behaviors than Android apps -- 91 percent of iOS apps exhibit at least one risky behavior, according to Appthority, compared to 80 percent of Android apps. "While Apple's mobile ecosystem is often considered safer in comparison to Android's 'open' platform, that's not the case in terms of apps' hunger for user data," the report states.

Specifically, 72 percent of the top free apps track the user's location, compared to 41 percent of paid apps. Seventy-eight percent of the most popular free Android apps identity the device's UDID, and even though Apple prohibits its developers from accessing the UDID, 5.5 of the tested iOS apps still do.

And while paid apps already generate revenue when purchased, 39 percent of paid iOS apps and 16 percent of paid Android apps still share data with ad networks -- and 59 percent of paid iOS apps and 24 percent of paid Android apps still support in-app purchasing.

"In analyzing both paid and free apps in our report, we've identified several new security trends within the global app ecosystem," Appthority co-founder and president Domingo Guerra said in a statement. "For instance, we measured how paid apps -- like free apps -- are now supporting in-app purchasing and sharing data with ad networks as a method of generating revenue, even if it means putting user and corporate data at risk. We also discovered several popular iOS apps that access the unique device identifier (or UDID), even though Apple strictly prohibits that activity because UDIDs can be linked back to the private user information and activity as they navigate across apps."