CVEs / CVE-2024-39891
CVE-2024-39891: Twilio Authy Information Disclosure Vulnerability
- Known exploited in the CISA KEV catalog since 23 Jul 2024
- medium 5.3 CVSS 3.1 (NVD)
- EPSS 1.66% chance of exploitation in the next 30 days, higher than 76% of CVEs (30 Oct 2026)
- Last changed at its sources
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Summary
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.
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.)
Affected and fixed versions
| Product | Affected | Fixed in |
|---|---|---|
| n/a n/a | n/a | — |
| twilio authy_2-factor_authentication | before 26.1.0 | 26.1.0 |
| twilio authy_2-factor_authentication | before 25.1.0 | 25.1.0 |
Exploitation
| In CISA KEV since | 23 Jul 2024 |
|---|---|
| Due date for US federal agencies | 13 Aug 2024 |
| Used in ransomware campaigns | Unknown |
| Required action | Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable. |
Severity
| CVSS 3.1 | 5.3 mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:NScored by NVD |
|---|---|
| Weakness | CWE-203 |
References
- CVE-2024-39891 on NVD
- CVE-2024-39891 in the CISA KEV catalog
- https://www.twilio.com/en-us/changelog/Security_Alert_Authy_App_Android_iOS (cited by CISA)
- https://cwe.mitre.org/data/definitions/203.html Technical Description
- https://www.bleepingcomputer.com/news/security/hackers-abused-api-to-verify-millions-of-authy-mfa-phone-numbers/ Press/Media Coverage
- https://www.twilio.com/docs/usage/security/reporting-vulnerabilities Product
- https://www.twilio.com/en-us/changelog Release Notes
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2024-39891 US Government Resource
Sources
Exploitation status from the CISA Known Exploited Vulnerabilities catalog. EPSS scores from FIRST. Descriptions, severity and references from the National Vulnerability Database. Open-source package versions from OSV (CC-BY 4.0). Text is shown as each source states it; Stackurity does not edit it. Check the vendor's advisory before acting.
This product uses data from the NVD API but is not endorsed or certified by the NVD.