🔒 Use isolated-vm

packages/variables/codeRunners.ts

@@ -0,0 +1,55 @@
+import { Variable } from './types'
+import ivm from 'isolated-vm'
+import { parseGuessedValueType } from './parseGuessedValueType'
+
+export const createCodeRunner = ({ variables }: { variables: Variable[] }) => {
+  const isolate = new ivm.Isolate()
+  const context = isolate.createContextSync()
+  const jail = context.global
+  jail.setSync('global', jail.derefInto())
+  variables.forEach((v) => {
+    jail.setSync(v.id, parseTransferrableValue(parseGuessedValueType(v.value)))
+  })
+  return (code: string) =>
+    context.evalClosureSync(
+      `return (function() {
+    return new Function($0)();
+  }())`,
+      [code],
+      { result: { copy: true }, timeout: 10000 }
+    )
+}
+
+export const createHttpReqResponseMappingRunner = (response: any) => {
+  const isolate = new ivm.Isolate()
+  const context = isolate.createContextSync()
+  const jail = context.global
+  jail.setSync('global', jail.derefInto())
+  jail.setSync('response', new ivm.ExternalCopy(response).copyInto())
+  return (expression: string) => {
+    return context.evalClosureSync(
+      `globalThis.evaluateExpression = function(expression) {
+        try {
+          // Use Function to safely evaluate the expression
+          const func = new Function('statusCode', 'data', 'return (' + expression + ')');
+          return func(response.statusCode, response.data);
+        } catch (err) {
+          throw new Error('Invalid expression: ' + err.message);
+        }
+      };
+      return evaluateExpression.apply(null, arguments);`,
+      [expression],
+      {
+        result: { copy: true },
+        timeout: 10000,
+      }
+    )
+  }
+}
+
+const parseTransferrableValue = (value: unknown) => {
+  if (typeof value === 'object') {
+    return new ivm.ExternalCopy(value).copyInto()
+  }
+  return value
+}

packages/variables/executeFunction.ts

@@ -4,9 +4,9 @@ import { parseGuessedValueType } from './parseGuessedValueType'
 import { isDefined } from '@typebot.io/lib'
 import { safeStringify } from '@typebot.io/lib/safeStringify'
 import { Variable } from './types'
-import vm from 'vm'
+import ivm from 'isolated-vm'
 
-const defaultTimeout = 10
+const defaultTimeout = 10 * 1000
 
 type Props = {
   variables: Variable[]
@@ -19,9 +19,9 @@ export const executeFunction = async ({
   body,
   args: initialArgs,
 }: Props) => {
-  const parsedBody = `(async function() {${parseVariables(variables, {
+  const parsedBody = parseVariables(variables, {
     fieldToParse: 'id',
-  })(body)}})()`
+  })(body)
 
   const args = (
     extractVariablesFromText(variables)(body).map((variable) => ({
@@ -40,21 +40,40 @@ export const executeFunction = async ({
     updatedVariables[key] = value
   }
 
-  const context = vm.createContext({
-    ...Object.fromEntries(args.map(({ id, value }) => [id, value])),
-    setVariable,
-    fetch,
-    setTimeout,
+  const isolate = new ivm.Isolate()
+  const context = isolate.createContextSync()
+  const jail = context.global
+  jail.setSync('global', jail.derefInto())
+  context.evalClosure(
+    'globalThis.setVariable = (...args) => $0.apply(undefined, args, { arguments: { copy: true }, promise: true, result: { copy: true, promise: true } })',
+    [new ivm.Reference(setVariable)]
+  )
+  context.evalClosure(
+    'globalThis.fetch = (...args) => $0.apply(undefined, args, { arguments: { copy: true }, promise: true, result: { copy: true, promise: true } })',
+    [
+      new ivm.Reference(async (...args: any[]) => {
+        // @ts-ignore
+        const response = await fetch(...args)
+        return response.text()
+      }),
+    ]
+  )
+  args.forEach(({ id, value }) => {
+    jail.setSync(id, value)
   })
-
-  const timeout = new Timeout()
+  const run = (code: string) =>
+    context.evalClosure(
+      `return (async function() {
+		const AsyncFunction = async function () {}.constructor;
+		return new AsyncFunction($0)();
+	}())`,
+      [code],
+      { result: { copy: true, promise: true }, timeout: defaultTimeout }
+    )
 
   try {
-    const output: unknown = await timeout.wrap(
-      await vm.runInContext(parsedBody, context),
-      defaultTimeout * 1000
-    )
-    timeout.clear()
+    const output = await run(parsedBody)
+    console.log('Output', output)
     return {
       output: safeStringify(output) ?? '',
       newVariables: Object.entries(updatedVariables)
@@ -86,33 +105,3 @@ export const executeFunction = async ({
     }
   }
 }
-
-class Timeout {
-  private ids: NodeJS.Timeout[]
-
-  constructor() {
-    this.ids = []
-  }
-
-  private set = (delay: number) =>
-    new Promise((_, reject) => {
-      const id = setTimeout(() => {
-        reject(`Script ${defaultTimeout}s timeout reached`)
-        this.clear(id)
-      }, delay)
-      this.ids.push(id)
-    })
-
-  wrap = (promise: Promise<any>, delay: number) =>
-    Promise.race([promise, this.set(delay)])
-
-  clear = (...ids: NodeJS.Timeout[]) => {
-    this.ids = this.ids.filter((id) => {
-      if (ids.includes(id)) {
-        clearTimeout(id)
-        return false
-      }
-      return true
-    })
-  }
-}

packages/variables/package.json

@@ -5,6 +5,7 @@
   "private": true,
   "dependencies": {
     "@typebot.io/lib": "workspace:*",
-    "@typebot.io/tsconfig": "workspace:*"
+    "@typebot.io/tsconfig": "workspace:*",
+    "isolated-vm": "4.7.2"
   }
 }

packages/variables/parseVariables.ts

@@ -1,8 +1,7 @@
 import { safeStringify } from '@typebot.io/lib/safeStringify'
 import { isDefined, isNotDefined } from '@typebot.io/lib/utils'
-import { parseGuessedValueType } from './parseGuessedValueType'
 import { Variable, VariableWithValue } from './types'
-import vm from 'vm'
+import { createCodeRunner } from './codeRunners'
 
 export type ParseVariablesOptions = {
   fieldToParse?: 'value' | 'id'
@@ -73,18 +72,10 @@ const evaluateInlineCode = (
   code: string,
   { variables }: { variables: Variable[] }
 ) => {
-  const evaluating = parseVariables(variables, { fieldToParse: 'id' })(
-    `(function() {
-      ${code.includes('return ') ? code : 'return ' + code}
-    })()`
-  )
   try {
-    const sandbox = vm.createContext({
-      ...Object.fromEntries(
-        variables.map((v) => [v.id, parseGuessedValueType(v.value)])
-      ),
-    })
-    return vm.runInContext(evaluating, sandbox)
+    return createCodeRunner({ variables })(
+      parseVariables(variables, { fieldToParse: 'id' })(code)
+    )
   } catch (err) {
     return parseVariables(variables)(code)
   }