Cotonti 1.0.0 (master branch, commit f43f1fc3) is vulnerable to Cross-Site Request Forgery in the Personal File Storage (PFS) module. In modules/pfs/inc/pfs.editfolder.php, the folder update action ('a=update') updates folder metadata (title, description, public/gallery flags) without calling cot_check_xg() to validate the anti-CSRF token. A remote attacker who lures an authenticated user into visiting a malicious page can force the browser to submit a forged request that modifies the victim's folder metadata, including making a private folder public.
Exploitability
AV:NAC:LAT:NPR:NUI:PVulnerable System
VC:LVI:LVA:NSubsequent System
SC:NSI:NSA:N5.3/CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:NAuthentication