CVE-2022-20481: WiFi Settings Preservation Leading to Information Disclosure in Android

In various Android versions, including Android-10, Android-11, Android-12, Android-12L, and Android-13, there exists a potential vulnerability through which WiFi settings may not be entirely removed after a device reset. This vulnerability, designated as CVE-2022-20481, could potentially lead to local information disclosure without the need for any additional execution privileges. For this vulnerability to be exploited, user interaction is required, meaning that affected users must take action to put their devices at risk.

This post aims to provide an in-depth understanding of CVE-2022-20481, including code snippets, links to relevant references, and detailed information about the exploit.

Code Snippet

The exploit primarily targets instances where residual data remains in multiple files after a device reset, thereby preserving WiFi settings. A rogue application would typically access these residual files to gain WiFi settings information. The code snippet below illustrates a potential information disclosure.

public class WiFiInfoDisclosure {
    public static void main(String[] args) {
        try {
            // Access residual files containing WiFi information
            File file = new File("path_to_residual_wifi_settings_file");
            FileReader fileReader = new FileReader(file);
            BufferedReader bufferedReader = new BufferedReader(fileReader);

            String line;
            while ((line = bufferedReader.readLine()) != null) {
                // Read the WiFi settings and potentially disclose the information
                System.out.println("WiFi setting: " + line);
            }

            bufferedReader.close();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

Original References

The Android team officially disclosed this vulnerability and assigned it the Android ID, A-241927115. It is part of the Android Security Bulletins that the team regularly issues to provide users comprehensive information about potential vulnerabilities and the appropriate remedial actions to mitigate or eliminate the risks associated with those vulnerabilities.

Android Security Bulletins: https://source.android.com/security/bulletin

Exploit Details

As previously mentioned, the exploit revolves around preserving WiFi settings even after a device is reset. These settings are stored in multiple files that are not properly cleaned up during the reset process, which can leave information such as SSIDs and potentially passwords vulnerable to malicious actors.

To exploit this vulnerability, a rogue application would require user interaction, like granting the application permissions to access certain files, which a user might unknowingly do. With this access, the application can then harvest WiFi settings from the residual files, giving a potential attacker sensitive information related to the user's WiFi networks.

Mitigation

It is crucial to ensure timely OS updates to safeguard against potential threats like CVE-2022-20481. As soon as this vulnerability was discovered, Android provided a patch to address the issue. Additionally, Android users should always be cautious about granting application permissions, and only permit access to applications from reputable sources. Avoid installing applications that request overly broad permissions that are unnecessary for their operation.

To stay up-to-date with Android Security Bulletins and receive notifications about newly discovered vulnerabilities, visit the Android Security Bulletin webpage and follow Android on social media platforms.

In conclusion, CVE-2022-20481 is a potentially problematic vulnerability in Android devices that could lead to local information disclosure. However, by staying informed and taking necessary precautions, users can mitigate the risks associated with this vulnerability and maintain a secure device environment.

Timeline

Published on: 02/28/2023 17:15:00 UTC
Last modified on: 03/09/2023 18:33:00 UTC