CVE-2024-39891 on CISA KEV

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

01What CISA says about this vulnerability

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…

02Required action — verbatim from CISA

Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

03Notes & references

• cwe.mitre.org — https://cwe.mitre.org/data/definitions/203.html
• www.twilio.com — https://www.twilio.com/docs/usage/security/reporting-vulnerabilities
• www.twilio.com — https://www.twilio.com/en-us/changelog
• www.bleepingcomputer.com — https://www.bleepingcomputer.com/news/security/hackers-abused-api-to-verify-mill…

04SARA's analyst layer — why this matters

This vulnerability is currently on the CISA KEV list, which CISA only adds CVEs to when there is reliable evidence of active exploitation in the wild. For federal civilian agencies, BOD 22-01 requires remediation by the due date above. For everyone else, KEV is the strongest "patch immediately" signal you can get from public threat intel.

05Affected products (summary)

Vendor	Product	Versions
n	a / n/a	n/a

06Detection

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