Pierluigi Paganini
June 17, 2015
More than 600 million Samsung smartphones could be opened to cyber attack due to the presence of a security flaw in the validation of the Swiftkey language pack updates. The security flaw, coded as CVE-2015-2865, affects to the mechanism used for adding new languages and upgrading existing ones in the mobile devices of the popular vendor.
The security issue affects several models of Samsung S mobile devices, including the Samsung Galaxy S4 Mini, S4, S5, and S6. According to the researchers at NowSecure, the update is sent to the smartphone via HTTP, but the transfer lack of any authentication mechanism allowing an attacker to run a man-in-the-middle (MitM) in order to replace the legitimate update with a malicious code. The attackers can inject their malicious payload whenever SwiftKey checks for a language pack update, a circumstance that occurs every few hours or on the device reboot.
“Samsung Galaxy S phones, including the S4 Mini, S4, S5, and S6, are pre-installed with a version of Swiftkey keyboard that is signed by Samsung to operate with system privileges. By design, Swiftkey periodically checks for language pack updates over HTTP. By intercepting such requests and modifying the necessary fields, an attacker can write arbitrary data to vulnerable devices.” states the US CERT.
The experts demonstrated that is possible to exploit the flaw to run an arbitrary on the target device without user interaction.
Another worrying consideration is related to the fact that updates are handled by the mobile OS with system privileges, this means that an attacker can exploit the flaw to acquire rights of a privileged user and install any kind of malicious apps without the user’s knowledge. The attackers can do much more, including eavesdropping on communications, access GPS data, steal sensitive information, access sensors data and of course control the camera and the microphone.
The experts reported the flaw to Samsung in December 2014 and started providing a patch to mobile carriers in early 2015. As usually happens in these cases, the different mobile carriers have different patch management processes and we have no information on the number of them that have already delivered the update to their customers.
According to the researchers, the giants Verizon and Sprint still haven’t pushed out the fix for the Samsung Galaxy S6 mobile phones, meanwhile AT&T hasn’t patched the Galaxy S4 Mini and T-Mobile hasn’t patched the Galaxy S5 devices.
The experts depicted several attack scenarios in order to exploit the flaw in the Samsung mobile devices, they can set up a rogue Wi-Fi access points or gain access to the victim’s local network. The attacker could be very easy for persistent attackers that are able to run DNS hijacking attackers, or that can have the access level of an ISP.
Actually the only way to mitigate the risk of exposure is to install a patch provided by the mobile carrier because the Swift keyboard is present in the mobile OS and cannot be disabled or uninstalled. Meantime, avoid using untrusted Wi-Fi networks.
“The Swift keyboard comes pre-installed on Samsung devices and cannot be disabled or uninstalled. Even when it is not used as the default keyboard, it can still be exploited.” states the post.
NowSecure has published a proof-of-concept (PoC) code to demonstrate the exploitation of the vulnerability, below the Video PoC of the attack:
(Security Affairs – Samsung, hacking)
