Twilio Authy Information Disclosure Vulnerability

[ Why it matters ]Priority signals

• Exploited in the wild: on CISA's Known Exploited Vulnerabilities list since 2024-07-23

[ Description ]Official 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.)

CISA: Twilio Authy contains an information disclosure vulnerability in its API that allows an unauthenticated endpoint to accept a request containing a phone number and respond with information about whether the phone number was registered with Authy.

[ Fixes ]Fixes and patches

CISA required action (US federal deadline 13 Aug 2024): Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.

[ References ]References

• cwe.mitre.org/data/definitions/203.htmlTechnical Description
• www.bleepingcomputer.com/news/security/hackers-abused-api-to-verify-millions-of-authy-m…Press/Media Coverage
• www.twilio.com/docs/usage/security/reporting-vulnerabilitiesProduct
• www.twilio.com/en-us/changelogRelease Notes
• www.cisa.gov/known-exploited-vulnerabilities-catalogUS Government Resource