While assignment of a user to a team (bracket) in CTFd should be possible only once, at the registration, a flaw in logic implementation allows an authenticated user to reset it's bracket and then pick a new one, joining another team while a competition is already ongoing
While assignment of a user to a team (bracket) in CTFd should be possible only once, at the registration, a flaw in logic implementation allows an authenticated user to reset it's bracket and then pick a new one, joining another team while a competition is already ongoing. This issue impacts releases from 3.7.0 up to 3.7.4 and was addressed by pull request 2636 https://github.com/CTFd/CTFd/pull/2636 included in 3.7.5 release.
Exploitability
AV:NAC:LAT:NPR:LUI:NVulnerable System
VC:NVI:LVA:NSubsequent System
SC:NSI:NSA:N5.3/CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:NOther