npm PraisonAI SandboxExecutor allowedCommands bypass via shell chaining
Date: 2026-06
Affected: npm/praisonai
Attack vector: command-injection
Category: vulnerability-disclosure
Severity: High
CWE: CWE-693
CWE-78
CWE-863
CVSS: 8.8 (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)

## Summary The published npm package `praisonai` exports `SandboxExecutor`, `CommandValidator`, and `sandboxExec` as "safe command execution with restrictions." When `allowedCommands` is configured, `CommandValidator` checks only the first whitespace-delimited token of the command string. `SandboxExecutor` then passes the entire original string to `spawn("sh", ["-c", command])`. With a policy that allows only `echo`, this direct command is correctly rejected: ```sh cat /tmp/marker ``` but this chained command is accepted and executed: ```sh echo allowed; cat /tmp/marker ``` The shell executes `cat` even though `cat` is not allowlisted. This bypasses the command allowlist and can execute arbitrary shell commands with the PraisonAI process privileges when an application, CLI workflow, or agent pipeline exposes sandbox command execution to lower-trust users, prompts, or model output. The PoV is deterministic and local-only. It creates and reads only a temporary marker file. ## Technical Details In `src/praisonai-ts/src/cli/features/sandbox-executor.ts`, `CommandValidator.validate()` normalizes the command and authorizes only the first whitespace token: ```ts const normalized = command.toLowerCase().trim(); if (this.allowedCommands) { const baseCmd = normalized.split(/\s+/)[0]; if (!this.allowedCommands.includes(baseCmd)) { return { valid: false, reason: `Command '${baseCmd}' not in allowlist` }; } } ``` The denylist does not generally reject shell separator


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