Decidim is a participatory democracy framework. Starting in version 0.4.rc3 and prior to version 2.0.9 of the devise_invitable gem, the invites feature allows users to accept the invitation for an unlimited amount of time through the password reset functionality. This issue creates vulnerable dependencies starting in version 0.0.1.alpha3 and prior to versions 0.26.9, 0.27.5, and 0.28.0 of the decidim, decidim-admin, and decidim-system gems. When using the password reset functionality, the devise_invitable gem always accepts the pending invitation if the user has been invited. The only check done is if the user has been invited but the code does not ensure that the pending invitation is still valid as defined by the invite_for expiry period. Decidim sets this configuration to 2.weeks so this configuration should be respected. The bug is in the devise_invitable gem and should be fixed there and the dependency should be upgraded in Decidim once the fix becomes available. devise_invitable to version 2.0.9 and above fix this issue. Versions 0.26.9, 0.27.5, and 0.28.0 of the decidim, decidim-admin, and decidim-system gems contain this fix. As a workaround, invitations can be cancelled directly from the database.
Exploitability
AV:NAC:HPR:HUI:RScope
S:UImpact
C:HI:HA:N5.7/CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:H/A:NOther