AstrBot Authentication Bypass Vulnerability via Username Spoofing in OpenAPI Chat Endpoint

An authentication bypass vulnerability has been identified in AstrBot versions through 4.25.5. The issue arises in the OpenAPI chat functionality, where the 'username' parameter can be manipulated to spoof identities. This vulnerability allows holders of 'chat'-scope API keys to impersonate administrators and execute commands reserved for them. The flaw exists in the API component, specifically within the 'OpenApiRoute.chat_send' function of 'astrbot/dashboard/routes/open_api.py'. The vulnerability can be exploited remotely, and has been publicly disclosed.

Impact

Exploitation of this vulnerability allows for unauthorized execution of admin-only commands by spoofing the sender identity in the OpenAPI chat interface. This was demonstrated by successfully executing the '/name' command, which created a persistent alias under the impersonated administrator's identity.

Reproduction

To reproduce this vulnerability, a valid 'chat'-scope API key is required. After authenticating with this API key, send a POST request to the '/api/v1/chat' endpoint, including a 'username' parameter set to 'astrbot' and a 'message' parameter containing the command to be executed. The request will be processed as if it came from an administrator, bypassing normal authorization checks.