Denial of wallet - Model Manipulation

[0xKiewicz]

What happened?

Requests to /api/agents/chat/openAI endpoint can be manipulated by the client, any model, temperature, tokens value will be accepted unless OpenAPI Key is restricted.
model field can be set to "o3-mini" instead of "gpt-4.1-nano", before sending the request to server. HTTP request will be easily accepted by the backend.
o3-mini is about 10x more expensive than gpt-4.1-nano.

Version Information

da3730b

Steps to Reproduce

1. Send prompt
2. Intercept HTTP request and manipulate model. For instance, from "gpt-4.1-mini" to "o3-mini" (or temperature/tokens...)
3. Forward request

What browsers are you seeing the problem on?

No response

Relevant log output

N/A

Screenshots

No response

Code of Conduct

• I agree to follow this project's Code of Conduct

[danny-avila]

On the latest version of LibreChat, as long as the model is available from the system's model list, it can be used freely.

If the model is then removed from the list, but attempted to be used, you should receive this message: