CVE-2024-39891
twilio authy_2-factor_authentication
Published 2 Jul 2024 · updated 17 Jun 2026 · Analyzed
Exploited in the wild
CISA added this to its Known Exploited Vulnerabilities catalog on 23 Jul 2024, with a remediation deadline of 13 Aug 2024 for US federal agencies.
Required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
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.)
References
- cwe.mitre.org/data/definitions/203.html · Technical Description
- www.bleepingcomputer.com/news/security/hackers-abused-api-to-verify-millions-of-authy-mfa-phone-numbers/ · Press/Media Coverage
- www.twilio.com/docs/usage/security/reporting-vulnerabilities · Product
- www.twilio.com/en-us/changelog · Release Notes
- www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2024-39891 · US Government Resource