The Voatz application 2020-01-01 for Android allows only 100 million different PINs, which makes it easier for attackers (after using root access to make a copy of the local database) to discover login credentials and voting history via an offline brute-force approach.

References

• https://nvd.nist.gov/vuln/detail/CVE-2020-8988
• https://blog.voatz.com/?p=1209
• https://internetpolicy.mit.edu/wp-content/uploads/2020/02/SecurityAnalysisOfVoatz_Public.pdf