CyberRota Analysis
AI-GeneratedThe vulnerability allows an attacker to exploit a race condition in the AshAuthentication system, enabling them to replay a leaked magic link's single-use token and authenticate as the intended user. This critical flaw arises from the lack of proper serialization in the token's validity check, leading to multiple concurrent redemptions being accepted. Organizations using ash_authentication versions between 3.9.0 and 4.15.0, as well as from 5.0.0-rc.0 to 5.0.0-rc.14, should prioritize patching this vulnerability to prevent unauthorized access.
Public Exploit Signal
A public exploit, PoC, GitHub repository or Metasploit reference was detected for this CVE.
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Original NVD Description
Time-of-check Time-of-use (TOCTOU) Race Condition vulnerability in team-alembic AshAuthentication allows an attacker holding a leaked magic link to replay its single-use token and authenticate as the target subject. A magic link configured with single_use_token?, which is the default, is meant to be redeemable exactly once, but nothing serialises the token's validity check against its consumption, so concurrent redemptions of one token all succeed and each yields a full user token. Sign-in verifies the JWT with Jwt.verify/4 and revokes it only afterwards: AshAuthentication.Strategy.MagicLink.SignInPreparation revokes in a Query.after_action callback, and AshAuthentication.Strategy.MagicLink.SignInChange in an after_transaction hook that runs once the sign-in has already committed. AshAuthentication.TokenResource.Actions.revoke/3 writes the revocation as an upsert, so a concurrent duplicate revocation silently succeeds instead of conflicting and no request ever loses the race. This issue affects ash_authentication: from 3.9.0 before 4.15.0 and from 5.0.0-rc.0 before 5.0.0-rc.14.