Plane is an open-source project management tool

Why it is Amber

• CVSS 9.8 critical
• Remotely exploitable without logging in

References

• https://github.com/makeplane/plane/commit/6220ba990b2276a1a1979d1d5df68f650b8b47ad
• https://github.com/makeplane/plane/pull/9297
• https://github.com/makeplane/plane/releases/tag/v1.4.0
• https://github.com/makeplane/plane/security/advisories/GHSA-4vj8-p63v-8p24

Original description

Plane is an open-source project management tool. Prior to 1.4.0, Plane's signup flow creates a logged-in User row for any submitted email without an out-of-band ownership check, while User.email is unique=True. The authenticated user can call GET /api/users/me/workspaces/invitations/, which returns each WorkspaceMemberInvite whose email matches request.user.email. WorkSpaceMemberInviteSerializer uses fields = "all", exposing the token that protects the invitation join endpoint. An unauthenticated attacker who knows a target's email can register an account using that address, enumerate pending invitations, and accept an invitation as the target, joining a workspace at the invited role. The term pre-auth describes the attacker's initial state: the attacker has no credential before signup, while the enumeration and join requests use the session created by that signup. This issue is fixed in 1.4.0.