PraisonAI v4.6.48 exposes the PraisonAIUI MCP client management API through the default UI host apps without authentication. A remote unauthenticated client can send POST /api/mcp/connect with a command and args field. The endpoint passes those values into the MCP stdio client, which starts the attacker-selected local process as the PraisonAI UI service user.
The issue is reachable through PraisonAI's hosted UI integration (praisonai ui, praisonai ui agents, praisonai claw, and any app using praisonai.integration.host_app.create_host_app() / build_host_app()). praisonai ui and related Typer UI commands bind to 0.0.0.0 by default.
Confirmed affected:
praisonai v4.6.48d5f1114aaf1a2e9f121a6e66b929149ca2201f1dv4.6.48aiui==0.3.121 from src/praisonai/uv.lockLikely affected:
aiui / praisonaiui create_app() through the PraisonAI UI host apps without authentication and includes the mcp dependency. I only confirmed the latest release during this audit.Reasoning:
AV: the vulnerable endpoint is an HTTP API route.AC: a single POST request is sufficient.PR: default UI host apps do not require credentials unless opt-in auth is configured.UI: no victim interaction is needed after the server is running.S: code executes in the PraisonAI UI server process context.C/I/A: arbitrary local command execution permits secret exfiltration, file tampering, and service disruption.PraisonAI depends on MCP by default and exposes PraisonAIUI via optional UI extras:
src/praisonai/pyproject.toml:11 includes base dependencies.src/praisonai/pyproject.toml:19 includes mcp>=1.20.0.src/praisonai/pyproject.toml:25 defines the ui extra with aiui>=0.3.121,<0.4.src/praisonai/pyproject.toml:197 defines the claw extra with aiui[all]>=0.3.121,<0.4.PraisonAI's UI commands bind externally by default and launch aiui run:
src/praisonai/praisonai/cli/commands/ui.py:114 sets host="0.0.0.0" for praisonai ui.src/praisonai/praisonai/cli/commands/ui.py:163 passes that host to aiui run.src/praisonai/praisonai/cli/commands/ui.py:186, :204, and :222 also default subcommands to 0.0.0.0.src/praisonai/praisonai/cli/commands/claw.py:41 defines the full dashboard command.src/praisonai/praisonai/cli/commands/claw.py:93 launches aiui run with the selected host.PraisonAI's default apps create the PraisonAIUI Starlette app without forcing authentication:
src/praisonai/praisonai/ui_chat/default_app.py:18 calls configure_host(...).src/praisonai/praisonai/ui_chat/default_app.py:142 exports app = create_host_app().src/praisonai/praisonai/claw/default_app.py:63 calls configure_host(...).src/praisonai/praisonai/claw/default_app.py:128 exports app = create_host_app().src/praisonai/praisonai/integration/host_app.py:174 imports praisonaiui.server.create_app.src/praisonai/praisonai/integration/host_app.py:180 returns create_app().In aiui==0.3.121, the exposed server registers the MCP routes and auth is opt-in:
praisonaiui/server.py:1483 defines api_mcp_connect.praisonaiui/server.py:1488 reads attacker-controlled JSON.praisonaiui/server.py:1491 accepts either command or url.praisonaiui/server.py:1496 calls connect_mcp_server(body).praisonaiui/server.py:2516 defines create_app(..., require_auth=False, ...).praisonaiui/server.py:2550 adds AuthEnforcementMiddleware, but it only enforces auth when AUTH_ENFORCE=true.praisonaiui/server.py:2769 registers /api/mcp/servers.praisonaiui/server.py:2770 registers /api/mcp/connect.The MCP feature converts the request body into a local process launch:
praisonaiui/features/mcp.py:325 defines connect_server(self, server_config).praisonaiui/features/mcp.py:330 chooses stdio transport when command is present.praisonaiui/features/mcp.py:332 constructs StdioMCPClient(command=server_config["command"], args=server_config.get("args", [])).praisonaiui/features/mcp.py:360 calls client.connect(), which invokes the MCP stdio transport and starts the process.PoC file: poc/praisonai-aiui-mcp-connect-rce.py
The PoC runs the PraisonAI host app in-process, sends the unauthenticated HTTP request, and asks the server to execute /usr/bin/touch /tmp/praisonai_host_app_mcp_touch_marker.txt. It does not contact an LLM provider and uses no credentials.
Observed output from the tested checkout with aiui==0.3.121 and mcp==1.25.0 available:
[19:19:55] server.py:229 WARNING No auth_token provided for Gateway server. Generated temporary token: gw_****650a. For production, set GATEWAY_AUTH_TOKEN.
[19:19:55] mcp.py:135 ERROR Failed to connect to MCP stdio server: 'tuple' object has no attribute 'initialize'
HTTP_STATUS= 200
RESPONSE= {"server":{"name":"poc-stdio-process-0","transport":"stdio","status":"error","tools":[],"last_error":"Connection failed"}}
SUCCESS_AT_ATTEMPT= 0
MARKER_EXISTS= True
MARKER_PATH= /tmp/praisonai_host_app_mcp_touch_marker.txt
The MCP handshake fails because aiui==0.3.121 is not compatible with the locked mcp==1.25.0 return shape, but the attacker-selected process is already started. Process startup can race the immediate teardown caused by this version mismatch, so the checked-in PoC retries the same unauthenticated request until /usr/bin/touch wins scheduling and creates the marker. The marker file proves local command execution despite the reported MCP connection error.
An operator runs:
pip install "praisonai[ui]"
praisonai ui
Because praisonai ui binds to 0.0.0.0 by default and the generated app does not require authentication by default, any host that can reach the UI port can send:
POST /api/mcp/connect
Content-Type: application/json
{
"name": "evil",
"command": "/usr/bin/touch",
"args": ["/tmp/pwned-by-ui-mcp"]
}
In a real attack, the command can be replaced with a shell, a credential exfiltration command, a file modification command, or a payload that starts a long-lived process as the PraisonAI UI server user.
Searched sources:
praisonai: 51 advisories returned.aiui: 0 advisories returned.praisonaiui: 0 advisories returned./api/mcp/connect, api_mcp_connect, StdioMCPClient, connect_mcp_server, and praisonaiui.features.mcp.PraisonAI StdioMCPClient, PraisonAI api_mcp_connect, PraisonAI /api/mcp/connect, PraisonAIUI /api/mcp/connect, and aiui StdioMCPClient: 0 results.MervinPraison/PraisonAI for exact endpoint/function/class terms. Only one unrelated PR was returned for /api/mcp/connect; no issue/PR matched api_mcp_connect, StdioMCPClient, connect_mcp_server, or praisonaiui.features.mcp.Why this is distinct from known PraisonAI advisories:
praisonai serve agents --api-key /agents auth bypass. This report targets POST /api/mcp/connect in the PraisonAIUI host app.MCPHandler.parse_mcp_command() command parsing. This finding uses praisonaiui.server.api_mcp_connect -> praisonaiui.features.mcp.connect_mcp_server -> StdioMCPClient.command/args from the remote HTTP API. MCP stdio servers should be configured only from trusted local configuration, not caller-supplied JSON./api/mcp/connect, /api/mcp/disconnect/*, and /api/mcp/servers regardless of AUTH_ENFORCE.0.0.0.0 to 127.0.0.1, or require an explicit --unsafe-expose style flag when binding externally without auth./api/mcp/connect cannot start a subprocess, including when AUTH_ENFORCE is unset.