Cyber security specialists from Check Point have revealed a new type of attack called Man-in-the-Disk (MitD), which exploits vulnerabilities in managing external memory applications on the Android OS. Vulnerable are mobile versions of translators from Google and Yandex, as well as the popular browser from Xiaomi.
How does Man-in-the-Disk work?
According to researchers, there are several reasons for the of the MitD attack. First, every application on Android can access data from another program contained in external memory. Secondly, most applications ask the user for permission to work with memory, and they usually agree, without thinking about the possible risk.
Check Point employees were able to recreate two versions of Man-in-the-Disk:
- The first option interferes with the files of the target application, loading malicious data into external memory. It causes an error in the program and leaves gaps for further malicious actions. In addition, this type of MitD allows you to obtain the permissions that the victim application had without additional actions:
Man in the DIsk Attack
- The second version of the attack replaces the temporary update files that applications store in external memory before they are installed. An attacker can force the program to install its malicious version or third-party malware
Man in the DIsk Attack
Which applications are vulnerable to attack?
Among the vulnerable applications there are: Google Translate, Google Voice Typing, Yandex Translate and Yandex Search, as well as Xiaomi Browser. It is noteworthy that the solutions from Google and Xiaomi are pre-installed on a large number of Android-devices.
How to defend yourself?
Check Point experts say that application developers, including Google, do not follow such security practices as the Android security guidelines. They recommend using the following Man-in-the-Disk protection:
- Verify input validation when processing files in external memory;
- Do not store executable files or classes in external memory;
- sign and cryptographically check files in external storage before dynamic loading.
In addition, the Check Point team believes that Android security should be strengthened at the system level, rather than software. Only low-level protection can help in preventing such attacks, the company believes.
After detecting the attack, experts sent letters to Google and Xiaomi with a description of the problem. The first quickly responded and already released security updates for vulnerable applications, while the latter preferred not to respond to the developers' letter.