Security firm FireEye has discovered a malicious version of the Vpon advertising SDK that provides support for intrusive commands that can allow a remote third-party to manipulate iOS devices.
Vpon is the name of an advertising SDK provided for Chinese and Taiwanese developers. The SDK was created to simplify the process of embedding Vpon ads in iOS apps.
The SDK was built using Apache Cordova, a mobile development framework for developing mobile apps using modern technologies like HTML5 and JavaScript. According to FireEye, the Vpon SDK contains functions that allow a malicious party to record audio or video, take screenshots on an iOS device, get device geolocation data, access the address book, interact with apps, and even steal and then upload data from the device to a remote server.
FireEye says that these functions are implemented with the help of Apache Cordova plugins, but are disabled in the final version of the SDK, and developers can't access them. Unfortunately, there is a place where developers can gain access to these functions, despite Vpon's protection measures. Developers can get an untethered version of the SDK via the AdsMogo service, an aggregator for various advertising SDKs.
FireEye says it detected 36 apps on the official App Store that use the Vpon SDK offered through AdsMogo. Exploitation of these apps can occur via a simple command delivered via an ad's JavaScript code. The vulnerable app where this ad is embedded reads the ad's JavaScript files using the Vpon SDK, which then translates this code into a malicious action based on its internal routines. The Apache Cordova plugins come into play by translating these JavaScript commands to Objective-C code, acting as an intermediary.
FireEye says it didn't detect any exploitation attempts via this SDK, but also said that Apple has failed to remove the reported apps. Furthermore, the security firm says that Vpon has remained unresponsive to all of its contact attempts and that the intrusive functions are still present in its SDK, even if they are limited in the official version.
Exploitation also possible via MitM attacks
Because the SDK carries out communications via HTTP, the attacker doesn't necessarily have to be in command of Vpon's servers, but can also run simple MitM scenarios and deliver malicious instructions to nearby devices.
"A third party ad library provider, Vpon, is stowing aggressive and risky code ability into the apps that adopt it as an ad-serving platform," FireEye's Jing Xie and Jimmy Su noted. "Third party libraries – ad libraries in particular – are often unvetted by the community. It is common and expected that app developers will integrate third party libraries into their apps, so developers should exert caution." Last year, there were several other cases were security researchers found similar malicious advertising SDKs, but for the Android OS.
