Description
ChatCLI before v1.215.2 contains an improper validation vulnerability in the MCP OAuth login flow that uses server-supplied Protected Resource Metadata as the resource indicator without checking it matches the configured server URL. A malicious MCP server can declare another resource on the same authorization server, obtain the user's bearer token for it, and replay that token against the other resource.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| diillson | ChatCLI | v1.159.0 – < v1.215.2 | v1.215.2 |
References
- GitHub Security Advisory (GHSA-95vg-3r9c-2v5q) vendor-advisory
- https://github.com/diillson/chatcli/commit/951fe24b8e090eae86bf8edb13a788916b1e6c91 patch
- ChatCLI v1.215.2 Release Notes release-notes
- https://github.com/diillson/chatcli/blob/359eb27debc4de78289a9662551a51ab4528e16c/cli/mcp/oauth.go#L477-L493 technical-description
- VulnCheck Advisory: ChatCLI before v1.215.2 Origin Validation Error via Unvalidated MCP OAuth Resource Indicator third-party-advisory