The GDPR cookies module for Backdrop CMS (before
1.x-1.3.5) doesn't sufficiently protect visitors from Cross Site Scripting (XSS) if a malicious value has been provided for the optional 'Info content' field for the YouTube service. This is mitigated by the fact that an attacker must have a role with the permission "Create a GDPR Cookies Service" or "Edit any GDPR Cookies Service" and a site must have added a YouTube service as configuration.
Exploitability
AV:NAC:HAT:PPR:HUI:AVulnerable System
VC:NVI:NVA:NSubsequent System
SC:NSI:LSA:L1.8/CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:A/VC:N/VI:N/VA:N/SC:N/SI:L/SA:LOther