OpenCost before 1.121.0 fails to authenticate the GET /helmValues endpoint, exposing base64-decoded HELM_VALUES environment variable containing cloud provider credentials. Additionally, adminAuthMiddleware fails open when ADMIN_TOKEN is unset, allowing unauthenticated attackers to modify GCP service account keys via POST /serviceKey to redirect billing calls.
Exploitability
AV:NAC:LAT:NPR:NUI:NVulnerable System
VC:HVI:NVA:NSubsequent System
SC:NSI:NSA:N8.7/CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:NAuthentication