Vulnerable cross-model authorization in juju. If a charm's cross-model permissions are revoked or expire, a malicious user who is able to update database records can mint an invalid macaroon that is incorrectly validated by the juju controller, enabling a charm to maintain otherwise revoked or expired permissions. This allows a charm to continue relating to another charm in a cross-model relation, and use their workload without their permission. No fix is available as of the time of writing.
Exploitability
AV:AAC:HAT:PPR:LUI:NVulnerable System
VC:LVI:LVA:LSubsequent System
SC:LSI:LSA:L2.1/CVSS:4.0/AV:A/AC:H/AT:P/PR:L/UI:N/VC:L/VI:L/VA:L/SC:L/SI:L/SA:L