Open Redirect in Better-Auth

CVE-2024-56734

Better Auth is an authentication library for TypeScript. An open redirect vulnerability has been identified in the verify email endpoint of all versions of Better Auth prior to v1.1.6, potentially allowing attackers to redirect users to malicious websites. This issue affects users relying on email verification links generated by the library. The verify email callback endpoint accepts a `callbackURL` parameter. Unlike other verification methods, email verification only uses JWT to verify and redirect without proper validation of the target domain. The origin checker is bypassed in this scenario because it only checks for `POST` requests. An attacker can manipulate this parameter to redirect users to arbitrary URLs controlled by the attacker. Version 1.1.6 contains a patch for the issue.

Vulnerability class: Open Redirect

EPSS: 0.004 (32.3th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2024-56734?
CVE-2024-56734 is a medium-severity vulnerability in Better-Auth, classified under URL Redirection to Untrusted Site (Open Redirect). CVSS score: 6.1/10. Published 2024-12-30.
How severe is CVE-2024-56734?
Medium severity. CVSS v3 base score is 6.1 out of 10.