CVE-2026-55177: CloudTAK: Authenticated full-read SSRF in the /api/esri* routes — user-controlled URL fetched with no IP-classification guard
Every route in the ESRI helper family (api/routes/esri.ts) takes a fully attacker-controlled URL from the request (POST /api/esri body url, and the portal / server / layer query parameters on the GET /api/esri/* routes) and passes it into EsriBase / EsriProxyPortal / EsriProxyServer / EsriProxyLayer in api/lib/esri.ts, which fetch it with the bare fetch from @tak-ps/etl. No IP / DNS / hostname classification is applied at any point, so the destination is never validated against private, loopback, or link-local ranges.
Any authenticated user (the routes only require Auth.is_auth(config, req, { anyResources: true }), i.e. any token, not an admin) can therefore make the CloudTAK server issue arbitrary outbound GET/POST requests to internal addresses such as the cloud instance-metadata service (169.254.169.254), loopback admin ports (127.0.0.1:<port>), and other hosts reachable only from inside the deployment VPC.
This is a full-read SSRF, not blind: on success the upstream JSON body is returned to the caller via res.json(...), and on failure the upstream error string is reflected verbatim as ESRI Server Error: <message>. An attacker can read cloud metadata (and the temporary IAM credentials the instance role exposes), enumerate internal services, and exfiltrate their response bodies.
The sniff() URL classifier provides no protection: it only pattern-matches the pathname (/rest, /arcgis/rest, /sharing/rest), so a URL like http://169.254.169.254/arcgis/rest or http://127.0.0.1:8500/rest passes sniff() and is fetched.
References
Code Behaviors & Features
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