RCE Bug in Android Remote Keyboard Apps With 2M Downloads Let Hackers Access keystrokes

Multiple critical vulnerabilities were found by the security researchers at Synopsys in three Android apps that enable users to control computer systems with Android devices. 

Furthermore, these critical vulnerabilities could be exploited by threat actors to expose key presses and to perform RCE (Remote Code Execution).

The three apps are quite popular and have more than two million downloads in the merged state. While the apps that are found vulnerable are:-

• PC Keyboard
• Lazy Mouse
• Telepad

While the research conducted by Synopsys security experts was shared with the app developers in August 2022 as a result of the findings.

After contacting the software vendors again in October 2022 and failing to get a response from them, the researchers finally published a security advisory.

It has been discovered that these three apps have the following types of flaws that have been introduced by CyRC research:-

• Missing authentication mechanisms
• Missing authorization
• Insecure communication

Vulnerabilities

The following are the flaws that affect each app in different ways:-

• CVE ID: CVE-2022-45477

Description: Telepad allows remote unauthenticated users to send instructions to the server to execute arbitrary code without any previous authorization or authentication. CVSS Score: 9.8 CVSS 3.1 vector: AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

• CVE ID: CVE-2022-45478

Description: Telepad allows an attacker (in a man-in-the-middle position between the server and a connected device) to see all data (including keypresses) in cleartext. CVSS Score: 5.1 CVSS 3.1 vector: AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

• CVE ID: CVE-2022-4547

Description: PC Keyboard allows remote unauthenticated users to send instructions to the server to execute arbitrary code without any previous authorization or authentication. CVSS Score: 9.8 CVSS 3.1 vector: AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

• CVE ID: CVE-2022-45480

Description: PC Keyboard allows an attacker (in a man-in-the-middle position between the server and a connected device) to see all data (including keypresses) in cleartext. CVSS Score: 5.1 CVSS 3.1 vector: AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

• CVE ID: CVE-2022-45481

Description: The default configuration of Lazy Mouse does not require a password, allowing remote unauthenticated users to execute arbitrary code with no prior authorization or authentication. CVSS Score: 9.8 CVSS 3.1 vector: AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

• CVE ID: CVE-2022-45482

Description: The Lazy Mouse server enforces weak password requirements and doesn’t implement rate limiting, allowing remote unauthenticated users to easily and quickly brute force the PIN and execute arbitrary commands. CVSS Score: 9.8 CVSS 3.1 vector: AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

• CVE ID: CVE-2022-45483

Description: Lazy Mouse allows an attacker (in a man-in-the-middle position between the server and a connected device) to see all data (including keypresses) in cleartext. CVSS Score: 5.1 CVSS 3.1 vector: AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Timeline

• August 13, 2022: Initial disclosure
• August 18, 2022: Follow-up communication
• October 12, 2022: Final follow-up communication
• November 30, 2022: Advisory published by Synopsys

Recommendation

The developers of all three of the affected applications have abandoned each of these apps, in other words, the developers are no longer supporting these apps. That’s why they meet the criteria for abandonware’s definition.

Continued use of these apps may put sensitive information at risk, and there is a high probability that it will be exposed. There is also a possibility that remote attackers could run arbitrary code on the device if they succeed in exploiting these critical vulnerabilities.

Make sure you read the privacy statement carefully before you install any alternative app. Additionally, users should also check the app reviews and check the date of the last update before installing any alternative app.

For now, there is a strong recommendation by the CyRC to remove these vulnerable applications as soon as possible to prevent any further exploitation.

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