PraisonAI: Remote Code Execution via Sandbox Escape in `codeMode` Tool
Date: 2026-06
Affected: npm/praisonai
Attack vector: sandbox-escape
Category: vulnerability-disclosure
Severity: Critical
CWE: CWE-94
CVSS: 9.8 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)

## Summary The `codeMode` tool in `src/praisonai-ts/src/tools/builtins/code-mode.ts` uses `new Function()` with a `with(sandbox)` pattern to execute LLM-generated code. The blocklist-based "sandbox" can be trivially bypassed via `Function('return this')()` to recover the global object, followed by `global.require()` with string concatenation to evade the blocklist regex. This allows full arbitrary code execution on the host system. This affects all deployments where the code-mode tool is enabled for agents. ## Details **Vulnerable code (lines 187–191):** ```typescript const fn = new Function( 'sandbox', `with (sandbox) { ${code} }` ); const result = fn(sandbox); ``` The `code` parameter comes from LLM tool call arguments (the `execute` method at line 104). Before execution, a regex-based blocklist is applied (lines 108–136): ```typescript const blockedPatterns = [ /require\s*\(\s*['"]child_process['"]\s*\)/, /require\s*\(\s*['"]fs['"]\s*\)/, /import\s+.*from\s+['"]child_process['"]/, /process\.exit/, /eval\s*\(/, ]; ``` **Three fundamental weaknesses:** 1. **`with(sandbox)` does not provide isolation.** The `with` statement in JavaScript adds an object to the scope chain but does NOT prevent accessing the global object. The sandbox object sets `process: undefined` and `require: undefined`, but these are recovered via the global scope: ```javascript const g = Function('return this')(); g.require('child_' + 'process') ``` 2. **Blocklist evasion v


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