Common Weakness Enumeration

CWE-918

Allowed

Server-Side Request Forgery (SSRF)

Abstraction: Base · Status: Incomplete

The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.

6271 vulnerabilities reference this CWE, most recent first.

GHSA-G3W3-X2XJ-4585

Vulnerability from github – Published: 2022-05-14 01:46 – Updated: 2022-05-14 01:46
VLAI
Details

admin/functions/remote.php in Interspire Email Marketer through 6.1.6 has Server Side Request Forgery (SSRF) via a what=importurl&url= request with an http or https URL. This also allows reading local files with a file: URL.

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2018-19651"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-918"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2018-11-28T22:29:00Z",
    "severity": "MODERATE"
  },
  "details": "admin/functions/remote.php in Interspire Email Marketer through 6.1.6 has Server Side Request Forgery (SSRF) via a what=importurl\u0026url= request with an http or https URL. This also allows reading local files with a file: URL.",
  "id": "GHSA-g3w3-x2xj-4585",
  "modified": "2022-05-14T01:46:42Z",
  "published": "2022-05-14T01:46:42Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2018-19651"
    },
    {
      "type": "WEB",
      "url": "https://medium.com/@namhb/ssrf-to-lfi-in-interspire-email-marketer-698a748462a9"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-G42R-M263-958H

Vulnerability from github – Published: 2026-08-28 12:30 – Updated: 2026-08-28 12:30
VLAI
Details

SiYuan versions before v3.8.1 contain a server-side request forgery vulnerability in the http_request and web_fetch agent tools that perform DNS resolution only at guard time without validating the connect-time resolution. Attackers can use DNS rebinding to answer the guard resolution with a public IP and the connect resolution with a private or metadata IP, bypassing the SSRF defense to access cloud instance metadata and internal services.

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2026-82234"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-918"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-28T12:16:33Z",
    "severity": "HIGH"
  },
  "details": "SiYuan versions before v3.8.1 contain a server-side request forgery vulnerability in the http_request and web_fetch agent tools that perform DNS resolution only at guard time without validating the connect-time resolution. Attackers can use DNS rebinding to answer the guard resolution with a public IP and the connect resolution with a private or metadata IP, bypassing the SSRF defense to access cloud instance metadata and internal services.",
  "id": "GHSA-g42r-m263-958h",
  "modified": "2026-08-28T12:30:26Z",
  "published": "2026-08-28T12:30:26Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/siyuan-note/siyuan/security/advisories/GHSA-x8gv-g2g3-65fj"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-82234"
    },
    {
      "type": "WEB",
      "url": "https://www.vulncheck.com/advisories/siyuan-before-3.8.1-ssrf-via-dns-rebinding-toctou"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:L/VA:N/SC:H/SI:L/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"
    }
  ]
}

GHSA-G44M-HPF4-VMRP

Vulnerability from github – Published: 2025-03-20 12:32 – Updated: 2025-03-21 16:41
VLAI
Summary
FastChat Server-Side Request Forgery vulnerability
Details

A Server-Side Request Forgery (SSRF) vulnerability was identified in the lm-sys/fastchat web server, specifically in the affected version git 2c68a13. This vulnerability allows an attacker to access internal server resources and data that are otherwise inaccessible, such as AWS metadata credentials.

Show details on source website

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "fschat"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "last_affected": "0.2.36"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2024-12376"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-918"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2025-03-21T16:41:12Z",
    "nvd_published_at": "2025-03-20T10:15:27Z",
    "severity": "HIGH"
  },
  "details": "A Server-Side Request Forgery (SSRF) vulnerability was identified in the lm-sys/fastchat web server, specifically in the affected version git 2c68a13. This vulnerability allows an attacker to access internal server resources and data that are otherwise inaccessible, such as AWS metadata credentials.",
  "id": "GHSA-g44m-hpf4-vmrp",
  "modified": "2025-03-21T16:41:12Z",
  "published": "2025-03-20T12:32:43Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2024-12376"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/lm-sys/FastChat"
    },
    {
      "type": "WEB",
      "url": "https://huntr.com/bounties/c9cc3f28-ee9f-4d2d-9ee5-8c6455a11892"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "FastChat Server-Side Request Forgery vulnerability"
}

GHSA-G46M-X4Q2-P642

Vulnerability from github – Published: 2022-05-24 17:42 – Updated: 2022-05-24 17:42
VLAI
Details

The MessageBundleWhiteList class of atlassian-gadgets before version 4.2.37, from version 4.3.0 before 4.3.14, from version 4.3.2.0 before 4.3.2.4, from version 4.4.0 before 4.4.12, and from version 5.0.0 before 5.0.1 allowed unexpected DNS lookups and requests to arbitrary services as it incorrectly obtained application base url information from the executing http request which could be attacker controlled.

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2020-36232"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-918"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2021-02-22T21:15:00Z",
    "severity": "MODERATE"
  },
  "details": "The MessageBundleWhiteList class of atlassian-gadgets before version 4.2.37, from version 4.3.0 before 4.3.14, from version 4.3.2.0 before 4.3.2.4, from version 4.4.0 before 4.4.12, and from version 5.0.0 before 5.0.1 allowed unexpected DNS lookups and requests to arbitrary services as it incorrectly obtained application base url information from the executing http request which could be attacker controlled.",
  "id": "GHSA-g46m-x4q2-p642",
  "modified": "2022-05-24T17:42:50Z",
  "published": "2022-05-24T17:42:50Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2020-36232"
    },
    {
      "type": "WEB",
      "url": "https://jira.atlassian.com/browse/JRASERVER-72025"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-G4CP-FJ5C-7599

Vulnerability from github – Published: 2026-09-25 09:31 – Updated: 2026-09-25 09:31
VLAI
Details

The Asset CleanUp: Page Speed Booster plugin for WordPress is vulnerable to Server-Side Request Forgery in all versions up to, and including, 1.4.0.5 via the 'page_url' parameter. This makes it possible for authenticated attackers, with administrator-level access and above, to make web requests to arbitrary locations originating from the web application and can be used to query and modify information from internal services. This vulnerability is only reachable when the plugin's dom_get_type setting has been configured to 'wp_remote_post' by an administrator.

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2026-12037"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-918"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-25T08:16:38Z",
    "severity": "MODERATE"
  },
  "details": "The Asset CleanUp: Page Speed Booster plugin for WordPress is vulnerable to Server-Side Request Forgery in all versions up to, and including, 1.4.0.5 via the \u0027page_url\u0027 parameter. This makes it possible for authenticated attackers, with administrator-level access and above, to make web requests to arbitrary locations originating from the web application and can be used to query and modify information from internal services. This vulnerability is only reachable when the plugin\u0027s dom_get_type setting has been configured to \u0027wp_remote_post\u0027 by an administrator.",
  "id": "GHSA-g4cp-fj5c-7599",
  "modified": "2026-09-25T09:31:07Z",
  "published": "2026-09-25T09:31:07Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-12037"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/browser/wp-asset-clean-up/tags/1.4.0.3/classes/Admin/MainAdmin.php#L1067"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/browser/wp-asset-clean-up/tags/1.4.0.3/classes/Admin/MainAdmin.php#L1095"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/browser/wp-asset-clean-up/tags/1.4.0.3/classes/Admin/MainAdmin.php#L315"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/browser/wp-asset-clean-up/tags/1.4.0.4/classes/Admin/MainAdmin.php#L1067"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/browser/wp-asset-clean-up/tags/1.4.0.4/classes/Admin/MainAdmin.php#L1095"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/browser/wp-asset-clean-up/tags/1.4.0.4/classes/Admin/MainAdmin.php#L315"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/changeset?reponame=\u0026old=3699024%40wp-asset-clean-up\u0026new=3699024%40wp-asset-clean-up"
    },
    {
      "type": "WEB",
      "url": "https://www.wordfence.com/threat-intel/vulnerabilities/id/af1e638d-9fc8-4584-a138-8d6316fbfcad?source=cve"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:L/A:N",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-G4FW-P4HW-GQ39

Vulnerability from github – Published: 2026-08-07 21:30 – Updated: 2026-08-07 21:30
VLAI
Details

A vulnerability has been found in HKUDS nanobot up to 0.2.1. This affects the function _download_image_data_url of the file nanobot/providers/image_generation.py of the component Provider-returned Image URL Handler. The manipulation leads to server-side request forgery. It is possible to initiate the attack remotely. The exploit has been disclosed to the public and may be used. The identifier of the patch is 5095. It is recommended to apply a patch to fix this issue. The vendor explains: "We confirm that provider-returned image URLs required the same SSRF protections applied to other network retrieval paths. (...) The patch is currently available on main and is planned for the next patch release, v0.3.1."

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2026-19246"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-918"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-07T21:17:27Z",
    "severity": "LOW"
  },
  "details": "A vulnerability has been found in HKUDS nanobot up to 0.2.1. This affects the function _download_image_data_url of the file nanobot/providers/image_generation.py of the component Provider-returned Image URL Handler. The manipulation leads to server-side request forgery. It is possible to initiate the attack remotely. The exploit has been disclosed to the public and may be used. The identifier of the patch is 5095. It is recommended to apply a patch to fix this issue. The vendor explains: \"We confirm that provider-returned image URLs required the same SSRF protections applied to other network retrieval paths. (...) The patch is currently available on main and is planned for the next patch release, v0.3.1.\"",
  "id": "GHSA-g4fw-p4hw-gq39",
  "modified": "2026-08-07T21:30:39Z",
  "published": "2026-08-07T21:30:39Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-19246"
    },
    {
      "type": "WEB",
      "url": "https://github.com/HKUDS/nanobot/pull/5095"
    },
    {
      "type": "WEB",
      "url": "https://gist.github.com/YLChen-007/44bc77ac259e461c6938cc6c286c4430"
    },
    {
      "type": "WEB",
      "url": "https://github.com/HKUDS/nanobot"
    },
    {
      "type": "WEB",
      "url": "https://vuldb.com/cve/CVE-2026-19246"
    },
    {
      "type": "WEB",
      "url": "https://vuldb.com/submit/865113"
    },
    {
      "type": "WEB",
      "url": "https://vuldb.com/vuln/387000"
    },
    {
      "type": "WEB",
      "url": "https://vuldb.com/vuln/387000/cti"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P/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"
    }
  ]
}

GHSA-G4RV-4M9P-4H3V

Vulnerability from github – Published: 2025-10-28 06:31 – Updated: 2025-10-28 06:31
VLAI
Details

The Auto Featured Image (Auto Post Thumbnail) plugin for WordPress is vulnerable to Server-Side Request Forgery in all versions up to, and including, 4.1.7 via the upload_to_library function. This makes it possible for authenticated attackers, with Author-level access and above, to make web requests to arbitrary locations originating from the web application and can be used to query and modify information from internal services. On Cloud instances, this issue allows for metadata retrieval.

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2025-10145"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-918"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2025-10-28T06:15:38Z",
    "severity": "HIGH"
  },
  "details": "The Auto Featured Image (Auto Post Thumbnail) plugin for WordPress is vulnerable to Server-Side Request Forgery in all versions up to, and including, 4.1.7 via the upload_to_library function. This makes it possible for authenticated attackers, with Author-level access and above, to make web requests to arbitrary locations originating from the web application and can be used to query and modify information from internal services. On Cloud instances, this issue allows for metadata retrieval.",
  "id": "GHSA-g4rv-4m9p-4h3v",
  "modified": "2025-10-28T06:31:05Z",
  "published": "2025-10-28T06:31:05Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-10145"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/browser/auto-post-thumbnail/tags/4.1.7/includes/class-apt.php#L821"
    },
    {
      "type": "WEB",
      "url": "https://www.wordfence.com/threat-intel/vulnerabilities/id/93acfae6-470b-4637-b76b-e1162b80253f?source=cve"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-G4VH-VMFC-JCRF

Vulnerability from github – Published: 2024-04-02 21:30 – Updated: 2026-04-01 18:31
VLAI
Details

Server-Side Request Forgery (SSRF) vulnerability in Kadence WP Gutenberg Blocks by Kadence Blocks.This issue affects Gutenberg Blocks by Kadence Blocks: from n/a through 3.2.25.

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2024-24888"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-918"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2024-04-02T19:15:47Z",
    "severity": "MODERATE"
  },
  "details": "Server-Side Request Forgery (SSRF) vulnerability in Kadence WP Gutenberg Blocks by Kadence Blocks.This issue affects Gutenberg Blocks by Kadence Blocks: from n/a through 3.2.25.",
  "id": "GHSA-g4vh-vmfc-jcrf",
  "modified": "2026-04-01T18:31:44Z",
  "published": "2024-04-02T21:30:27Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2024-24888"
    },
    {
      "type": "WEB",
      "url": "https://patchstack.com/database/Wordpress/Plugin/kadence-blocks/vulnerability/wordpress-gutenberg-blocks-by-kadence-blocks-plugin-3-2-25-server-side-request-forgery-ssrf-vulnerability?_s_id=cve"
    },
    {
      "type": "WEB",
      "url": "https://patchstack.com/database/vulnerability/kadence-blocks/wordpress-gutenberg-blocks-by-kadence-blocks-plugin-3-2-25-server-side-request-forgery-ssrf-vulnerability?_s_id=cve"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-G53G-Q539-93CV

Vulnerability from github – Published: 2022-05-06 00:00 – Updated: 2022-05-24 20:52
VLAI
Summary
Server-Side Request Forgery in scout-browser
Details

Pypi package scout-browser (GitHub repository clinical-genomics/scout) prior to v4.52 is vulnerable to server-side request forgery. An attacker could make the application perform arbitrary requests to steal cookies, request access to private areas, or lead to cross-site scripting.

Show details on source website

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "scout-browser"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.52"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2022-1592"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-918"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2022-05-24T20:52:03Z",
    "nvd_published_at": "2022-05-05T11:15:00Z",
    "severity": "HIGH"
  },
  "details": "Pypi package scout-browser (GitHub repository clinical-genomics/scout) prior to v4.52 is vulnerable to server-side request forgery. An attacker could make the application perform arbitrary requests to steal cookies, request access to private areas, or lead to cross-site scripting.",
  "id": "GHSA-g53g-q539-93cv",
  "modified": "2022-05-24T20:52:03Z",
  "published": "2022-05-06T00:00:49Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2022-1592"
    },
    {
      "type": "WEB",
      "url": "https://github.com/Clinical-Genomics/scout/issues/3325"
    },
    {
      "type": "WEB",
      "url": "https://github.com/Clinical-Genomics/scout/pull/3326"
    },
    {
      "type": "WEB",
      "url": "https://github.com/clinical-genomics/scout/commit/b0ef15f4737d0c801154c1991b52ff5cab4f5c83"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/clinical-genomics/scout"
    },
    {
      "type": "WEB",
      "url": "https://huntr.dev/bounties/352b39da-0f2e-415a-9793-5480cae8bd27"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Server-Side Request Forgery in scout-browser"
}

GHSA-G569-3CP3-JXR8

Vulnerability from github – Published: 2026-09-04 18:31 – Updated: 2026-09-04 18:31
VLAI
Details

IBM Langflow OSS 1.0.0 through 1.11.2 could allow a remote attacker to obtain sensitive information due to server-side request forgery.

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2026-19305"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-918"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-04T16:17:24Z",
    "severity": "HIGH"
  },
  "details": "IBM Langflow OSS 1.0.0 through 1.11.2 could allow a remote attacker to obtain sensitive information due to server-side request forgery.",
  "id": "GHSA-g569-3cp3-jxr8",
  "modified": "2026-09-04T18:31:21Z",
  "published": "2026-09-04T18:31:21Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-19305"
    },
    {
      "type": "WEB",
      "url": "https://www.ibm.com/support/pages/node/7285639"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N",
      "type": "CVSS_V3"
    }
  ]
}

No mitigation information available for this CWE.

CAPEC-664: Server Side Request Forgery

An adversary exploits improper input validation by submitting maliciously crafted input to a target application running on a server, with the goal of forcing the server to make a request either to itself, to web services running in the server’s internal network, or to external third parties. If successful, the adversary’s request will be made with the server’s privilege level, bypassing its authentication controls. This ultimately allows the adversary to access sensitive data, execute commands on the server’s network, and make external requests with the stolen identity of the server. Server Side Request Forgery attacks differ from Cross Site Request Forgery attacks in that they target the server itself, whereas CSRF attacks exploit an insecure user authentication mechanism to perform unauthorized actions on the user's behalf.