rails_multisite provides multi-db support for Rails applications. In affected versions this vulnerability impacts any Rails applications using rails_multisite alongside Rails' signed/encrypted cookies. Depending on how the application makes use of these cookies, it may be possible for an attacker to re-use cookies on different 'sites' within a multi-site Rails application. The issue has been patched in v4 of the rails_multisite gem. Note that this upgrade will invalidate all previous signed/encrypted cookies. The impact of this invalidation will vary based on the application architecture.
Exploitability
AV:NAC:LPR:LUI:NScope
S:UImpact
C:HI:LA:H8.3/CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:HInformation Disclosure
Other