Description
mcp-remote 0.8.0 through 0.14.3 contains a cleartext transmission vulnerability in authorizeWithDeviceCode that sends client secrets and receives tokens without enforcing HTTPS endpoints. When discovered device authorization and token endpoints are non-loopback http URLs, on-path network attackers can capture the client secret plus issued access and refresh tokens.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| punkpeye | mcp-remote | 0.8.0 – ≤ 0.14.3 | — |
References
- https://hackmd.io/@haind03/punkpeye-mcp-remote-device-code-cleartext-oauth-transport third-party-advisory
- https://github.com/punkpeye/mcp-remote/blob/v0.14.3/src/lib/device-authorization.ts#L64-L170 technical-description
- https://github.com/punkpeye/mcp-remote/blob/v0.14.3/src/lib/client-credentials.ts#L37-L47 technical-description
- https://github.com/punkpeye/mcp-remote product
- VulnCheck Advisory: mcp-remote 0.8.0 through 0.14.3 Cleartext Credential Transmission via --device-code OAuth Grant third-party-advisory