GHSA-p69m-4f92-2v84: PraisonAI: Remote Code Execution via Sandbox Escape in `codeMode` Tool

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): 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): 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: const g = Function('return this')(); g.require('child_' + 'process') 2. Blocklist evasion via string concatenation. The regex /require\s*\(\s*['"]child_process['"]\s*\)/ requires the literal string 'child_process' or "child_process" inside require(). Using require('child_' + 'process') bypasses this because the regex sees a variable concatenation, not a literal string. 3. Function('return this')() is not blocked. None of the blocklist patterns match Function(, return this, or global.require. PoC Setup: Clean checkout at commit d5f1114a, Node.js v20.20.0 (tested environment). Positive trigger — full RCE with sandbox escape (OBSERVED OUTPUT): // This code bypasses ALL blocklist patterns and achieves RCE