[GHSA-9c47-m6qq-7p4h] Prototype Pollution in JSON5 via Parse Method

advisories/github-reviewed/2022/12/GHSA-9c47-m6qq-7p4h/GHSA-9c47-m6qq-7p4h.json

@@ -1,13 +1,13 @@
 {
   "schema_version": "1.3.0",
   "id": "GHSA-9c47-m6qq-7p4h",
-  "modified": "2022-12-29T01:51:03Z",
+  "modified": "2023-01-02T16:29:57Z",
   "published": "2022-12-29T01:51:03Z",
   "aliases": [
     "CVE-2022-46175"
   ],
   "summary": "Prototype Pollution in JSON5 via Parse Method",
-  "details": "The `parse` method of the JSON5 library before and including version `2.2.1` does not restrict parsing of keys named `__proto__`, allowing specially crafted strings to pollute the prototype of the resulting object.\n\nThis vulnerability pollutes the prototype of the object returned by `JSON5.parse` and not the global Object prototype, which is the commonly understood definition of Prototype Pollution. However, polluting the prototype of a single object can have significant security impact for an application if the object is later used in trusted operations.\n\n## Impact\nThis vulnerability could allow an attacker to set arbitrary and unexpected keys on the object returned from `JSON5.parse`. The actual impact will depend on how applications utilize the returned object and how they filter unwanted keys, but could include denial of service, cross-site scripting, elevation of privilege, and in extreme cases, remote code execution.\n\n## Mitigation\nThis vulnerability is patched in json v2.2.2 and later.\n\n## Details\nSuppose a developer wants to allow users and admins to perform some risky operation, but they want to restrict what non-admins can do. To accomplish this, they accept a JSON blob from the user, parse it using `JSON5.parse`, confirm that the provided data does not set some sensitive keys, and then performs the risky operation using the validated data:\n\n```js\nconst JSON5 = require('json5');\n\nconst doSomethingDangerous = (props) => {\n  if (props.isAdmin) {\n    console.log('Doing dangerous thing as admin.');\n  } else {\n    console.log('Doing dangerous thing as user.');\n  }\n};\n\nconst secCheckKeysSet = (obj, searchKeys) => {\n  let searchKeyFound = false;\n  Object.keys(obj).forEach((key) => {\n    if (searchKeys.indexOf(key) > -1) {\n      searchKeyFound = true;\n    }\n  });\n  return searchKeyFound;\n};\n\nconst props = JSON5.parse('{\"foo\": \"bar\"}');\nif (!secCheckKeysSet(props, ['isAdmin', 'isMod'])) {\n  doSomethingDangerous(props); // \"Doing dangerous thing as user.\"\n} else {\n  throw new Error('Forbidden...');\n}\n```\n\nIf an attacker attempts to set the `isAdmin` key, their request will be rejected:\n\n```js\nconst props = JSON5.parse('{\"foo\": \"bar\", \"isAdmin\": true}');\nif (!secCheckKeysSet(props, ['isAdmin', 'isMod'])) {\n  doSomethingDangerous(props);\n} else {\n  throw new Error('Forbidden...'); // Error: Forbidden...\n}\n```\n\nHowever, attackers can instead set the `__proto__` key to `{\"isAdmin\": true}`. `JSON5` will parse this key and will set the `isAdmin` key on the prototype of the returned object, allowing the attacker to bypass the security check and run their request as an admin:\n\n```js\nconst props = JSON5.parse('{\"foo\": \"bar\", \"__proto__\": {\"isAdmin\": true}}');\nif (!secCheckKeysSet(props, ['isAdmin', 'isMod'])) {\n  doSomethingDangerous(props); // \"Doing dangerous thing as admin.\"\n} else {\n  throw new Error('Forbidden...');\n}\n```\n",
+  "details": "The `parse` method of the JSON5 library before and including versions `2.2.1` and `1.0.2` does not restrict parsing of keys named `__proto__`, allowing specially crafted strings to pollute the prototype of the resulting object.\n\nThis vulnerability pollutes the prototype of the object returned by `JSON5.parse` and not the global Object prototype, which is the commonly understood definition of Prototype Pollution. However, polluting the prototype of a single object can have significant security impact for an application if the object is later used in trusted operations.\n\n## Impact\nThis vulnerability could allow an attacker to set arbitrary and unexpected keys on the object returned from `JSON5.parse`. The actual impact will depend on how applications utilize the returned object and how they filter unwanted keys, but could include denial of service, cross-site scripting, elevation of privilege, and in extreme cases, remote code execution.\n\n## Mitigation\nThis vulnerability is patched in json v2.2.2 and later. The patch has also be backported to v1.0.2 and later.\n\n## Details\nSuppose a developer wants to allow users and admins to perform some risky operation, but they want to restrict what non-admins can do. To accomplish this, they accept a JSON blob from the user, parse it using `JSON5.parse`, confirm that the provided data does not set some sensitive keys, and then performs the risky operation using the validated data:\n\n```js\nconst JSON5 = require('json5');\n\nconst doSomethingDangerous = (props) => {\n  if (props.isAdmin) {\n    console.log('Doing dangerous thing as admin.');\n  } else {\n    console.log('Doing dangerous thing as user.');\n  }\n};\n\nconst secCheckKeysSet = (obj, searchKeys) => {\n  let searchKeyFound = false;\n  Object.keys(obj).forEach((key) => {\n    if (searchKeys.indexOf(key) > -1) {\n      searchKeyFound = true;\n    }\n  });\n  return searchKeyFound;\n};\n\nconst props = JSON5.parse('{\"foo\": \"bar\"}');\nif (!secCheckKeysSet(props, ['isAdmin', 'isMod'])) {\n  doSomethingDangerous(props); // \"Doing dangerous thing as user.\"\n} else {\n  throw new Error('Forbidden...');\n}\n```\n\nIf an attacker attempts to set the `isAdmin` key, their request will be rejected:\n\n```js\nconst props = JSON5.parse('{\"foo\": \"bar\", \"isAdmin\": true}');\nif (!secCheckKeysSet(props, ['isAdmin', 'isMod'])) {\n  doSomethingDangerous(props);\n} else {\n  throw new Error('Forbidden...'); // Error: Forbidden...\n}\n```\n\nHowever, attackers can instead set the `__proto__` key to `{\"isAdmin\": true}`. `JSON5` will parse this key and will set the `isAdmin` key on the prototype of the returned object, allowing the attacker to bypass the security check and run their request as an admin:\n\n```js\nconst props = JSON5.parse('{\"foo\": \"bar\", \"__proto__\": {\"isAdmin\": true}}');\nif (!secCheckKeysSet(props, ['isAdmin', 'isMod'])) {\n  doSomethingDangerous(props); // \"Doing dangerous thing as admin.\"\n} else {\n  throw new Error('Forbidden...');\n}\n```\n",
   "severity": [
 
   ],
@@ -22,14 +22,33 @@
           "type": "ECOSYSTEM",
           "events": [
             {
-              "introduced": "0"
+              "introduced": "2.0.0"
             },
             {
               "fixed": "2.2.2"
             }
           ]
         }
       ]
+    },
+    {
+      "package": {
+        "ecosystem": "npm",
+        "name": "json5"
+      },
+      "ranges": [
+        {
+          "type": "ECOSYSTEM",
+          "events": [
+            {
+              "introduced": "0"
+            },
+            {
+              "fixed": "1.0.2"
+            }
+          ]
+        }
+      ]
     }
   ],
   "references": [