From 35f7c7cb3cec848b5899b7ba097eb34c14c3d2b2 Mon Sep 17 00:00:00 2001
From: James Gowdy <jgowdy@elastic.co>
Date: Wed, 2 Oct 2024 08:47:19 +0100
Subject: [PATCH] [ML] Various fixes for possible prototype pollution
 vulnerabilities (#194529)

Fixes potential prototype pollution vulnerability in `setNestedProperty`
function.
Fixes incomplete string escaping issue in ML's saved object service.

(cherry picked from commit d1f24b050b53cc7b13fbc47b6de3c5f69606e88e)
---
 .../ml/nested_property/src/set_nested_property.test.ts | 10 ++++++++++
 .../ml/nested_property/src/set_nested_property.ts      |  6 ++++++
 x-pack/plugins/ml/server/saved_objects/service.ts      |  4 ++--
 3 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/x-pack/packages/ml/nested_property/src/set_nested_property.test.ts b/x-pack/packages/ml/nested_property/src/set_nested_property.test.ts
index 43996f603ffa0..963b0611197db 100644
--- a/x-pack/packages/ml/nested_property/src/set_nested_property.test.ts
+++ b/x-pack/packages/ml/nested_property/src/set_nested_property.test.ts
@@ -68,5 +68,15 @@ describe('object_utils', () => {
 
     const test11 = setNestedProperty(getFalseyObject(), 'the.other_nested.value', 'update');
     expect(test11.the.other_nested.value).toBe('update');
+
+    expect(() => {
+      setNestedProperty(getTestObj(), 'the.__proto__', 'update');
+    }).toThrow('Invalid accessor');
+    expect(() => {
+      setNestedProperty(getTestObj(), 'the.prototype', 'update');
+    }).toThrow('Invalid accessor');
+    expect(() => {
+      setNestedProperty(getTestObj(), 'the.constructor', 'update');
+    }).toThrow('Invalid accessor');
   });
 });
diff --git a/x-pack/packages/ml/nested_property/src/set_nested_property.ts b/x-pack/packages/ml/nested_property/src/set_nested_property.ts
index b963983cb16ab..6c692cb3a0a08 100644
--- a/x-pack/packages/ml/nested_property/src/set_nested_property.ts
+++ b/x-pack/packages/ml/nested_property/src/set_nested_property.ts
@@ -5,9 +5,15 @@
  * 2.0.
  */
 
+const INVALID_ACCESSORS = ['__proto__', 'prototype', 'constructor'];
+
 export const setNestedProperty = (obj: Record<string, any>, accessor: string, value: any) => {
   let ref = obj;
   const accessors = accessor.split('.');
+  if (accessors.some((a) => INVALID_ACCESSORS.includes(a))) {
+    throw new Error('Invalid accessor');
+  }
+
   const len = accessors.length;
   for (let i = 0; i < len - 1; i++) {
     const attribute = accessors[i];
diff --git a/x-pack/plugins/ml/server/saved_objects/service.ts b/x-pack/plugins/ml/server/saved_objects/service.ts
index e6c32f2bc6531..3e0f81a8ba13b 100644
--- a/x-pack/plugins/ml/server/saved_objects/service.ts
+++ b/x-pack/plugins/ml/server/saved_objects/service.ts
@@ -328,7 +328,7 @@ export function mlSavedObjectServiceFactory(
       if (id.match('\\*') === null) {
         return jobIds.includes(id);
       }
-      const regex = new RegExp(id.replace('*', '.*'));
+      const regex = new RegExp(id.replaceAll('*', '.*'));
       return jobIds.some((jId) => typeof jId === 'string' && regex.exec(jId));
     });
   }
@@ -640,7 +640,7 @@ export function mlSavedObjectServiceFactory(
       if (id.match('\\*') === null) {
         return modelIds.includes(id);
       }
-      const regex = new RegExp(id.replace('*', '.*'));
+      const regex = new RegExp(id.replaceAll('*', '.*'));
       return modelIds.some((jId) => typeof jId === 'string' && regex.exec(jId));
     });
   }