Better Auth is an authentication and authorization library for TypeScript

Why it is Amber

• CVSS 9.1 critical
• Remotely exploitable without logging in

References

• https://github.com/better-auth/better-auth/commit/ac54bfd67821a7607533af2059858b12bc54e26a
• https://github.com/better-auth/better-auth/pull/11494
• https://github.com/better-auth/better-auth/releases/tag/v1.7.7
• https://github.com/better-auth/better-auth/security/advisories/GHSA-965c-763c-88jm

Original description

Better Auth is an authentication and authorization library for TypeScript. From 1.4.0-beta.18 until 1.7.7, deployments that enable Magic Link with storeToken set to plain, or with storeToken set to hashed and the global verification.storeIdentifier setting also set to hashed, enable a built-in social or Generic OAuth provider, and use account.storeStateStrategy set to database can accept an OAuth sign-in state value as a Magic Link token. These settings can cause Magic Link verification records and OAuth state to resolve to the same stored identifier, allowing an unauthenticated attacker to start OAuth sign-in for a known email address and redeem the returned state through Magic Link without controlling the mailbox or completing the provider callback. The attacker can obtain a normal session for an existing user, or create an account incorrectly marked as email verified when sign-up is enabled. This issue is fixed in version 1.7.7.