CVE-2024-39891
Description
In the Twilio Authy API, accessed by Authy Android before 25.1.0 and Authy iOS before 26.1.0, an unauthenticated endpoint provided access to certain phone-number data, as exploited in the wild in June 2024. Specifically, the endpoint accepted a stream of requests containing phone numbers, and responded with information about whether each phone number was registered with Authy. (Authy accounts were not compromised, however.)
Summary dbcve.org
An unauthenticated API endpoint in Authy mobile apps (Android <25.1.0, iOS <26.1.0) allowed attackers to submit phone numbers and receive responses indicating whether each number was registered with Authy, enabling phone number enumeration. This information disclosure was actively exploited in the wild in June 2024, though Authy accounts themselves were not compromised.
Mitigation
Update Authy Android to version 25.1.0 or later and Authy iOS to version 26.1.0 or later from their respective app stores. Consider monitoring for suspicious enumeration activity targeting your phone numbers.