Common Weakness Enumeration

CWE-601

Allowed

URL Redirection to Untrusted Site ('Open Redirect')

Abstraction: Base · Status: Draft

The web application accepts a user-controlled input that specifies a link to an external site, and uses that link in a redirect.

2561 vulnerabilities reference this CWE, most recent first.

GHSA-VHX4-2R84-67H4

Vulnerability from github – Published: 2026-09-06 12:30 – Updated: 2026-09-06 12:30
VLAI
Details

h3 versions before 2.0.1-rc.18 contain an open redirect vulnerability in the redirectBack() utility that fails to sanitize protocol-relative paths in the Referer header pathname. Attackers can craft a same-origin URL with a double-slash path segment that passes origin validation but produces a Location header interpreted by browsers as a protocol-relative redirect to an external domain.

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2026-86205"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-601"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-06T12:17:15Z",
    "severity": "MODERATE"
  },
  "details": "h3 versions before 2.0.1-rc.18 contain an open redirect vulnerability in the redirectBack() utility that fails to sanitize protocol-relative paths in the Referer header pathname. Attackers can craft a same-origin URL with a double-slash path segment that passes origin validation but produces a Location header interpreted by browsers as a protocol-relative redirect to an external domain.",
  "id": "GHSA-vhx4-2r84-67h4",
  "modified": "2026-09-06T12:30:23Z",
  "published": "2026-09-06T12:30:23Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/h3js/h3/security/advisories/GHSA-fp4x-ggrf-wmc6"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-86205"
    },
    {
      "type": "WEB",
      "url": "https://www.vulncheck.com/advisories/h3-before-2.0.1-rc.18-open-redirect-via-redirectback"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/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"
    }
  ]
}

GHSA-VJ26-HH8V-H6GR

Vulnerability from github – Published: 2021-11-24 00:00 – Updated: 2024-02-28 00:02
VLAI
Details

Dell EMC CloudLink 7.1 and all prior versions contain a HTML and Javascript Injection Vulnerability. A remote low privileged attacker, may potentially exploit this vulnerability, directing end user to arbitrary and potentially malicious websites.

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2021-36332"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-601"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2021-11-23T20:15:00Z",
    "severity": "MODERATE"
  },
  "details": "Dell EMC CloudLink 7.1 and all prior versions contain a HTML and Javascript Injection Vulnerability. A remote low privileged attacker, may potentially exploit this vulnerability, directing end user to arbitrary and potentially malicious websites.",
  "id": "GHSA-vj26-hh8v-h6gr",
  "modified": "2024-02-28T00:02:45Z",
  "published": "2021-11-24T00:00:39Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2021-36332"
    },
    {
      "type": "WEB",
      "url": "https://www.dell.com/support/kbdoc/en-us/000193031/https-dellservices-lightning-force-com-one-one-app"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-VJ4G-QPP7-2F4F

Vulnerability from github – Published: 2026-04-04 15:30 – Updated: 2026-04-04 21:30
VLAI
Details

Microsoft 7 Tik 1.0.1.0 contains a denial of service vulnerability that allows attackers to crash the application by submitting excessively long input strings to the search functionality. Attackers can paste a buffer of 7700 characters into the search bar to trigger an application crash.

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2018-25245"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-601"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-04-04T14:16:20Z",
    "severity": "HIGH"
  },
  "details": "Microsoft 7 Tik 1.0.1.0 contains a denial of service vulnerability that allows attackers to crash the application by submitting excessively long input strings to the search functionality. Attackers can paste a buffer of 7700 characters into the search bar to trigger an application crash.",
  "id": "GHSA-vj4g-qpp7-2f4f",
  "modified": "2026-04-04T21:30:27Z",
  "published": "2026-04-04T15:30:20Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2018-25245"
    },
    {
      "type": "WEB",
      "url": "https://www.exploit-db.com/exploits/46197"
    },
    {
      "type": "WEB",
      "url": "https://www.microsoft.com/store/productId/9NQL2QC8S935"
    },
    {
      "type": "WEB",
      "url": "https://www.vulncheck.com/advisories/7-tik-denial-of-service-via-search"
    },
    {
      "type": "WEB",
      "url": "https://www.vulncheck.com/advisories/microsoft-7-tik-denial-of-service-via-search"
    }
  ],
  "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"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/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"
    }
  ]
}

GHSA-VJ52-JGG8-WG96

Vulnerability from github – Published: 2021-12-25 00:00 – Updated: 2022-01-11 00:02
VLAI
Details

Open redirect vulnerability in GroupSession Free edition ver5.1.1 and earlier, GroupSession byCloud ver5.1.1 and earlier, and GroupSession ZION ver5.1.1 and earlier allows a remote unauthenticated attacker to redirect users to arbitrary web sites and conduct phishing attacks by having a user to access a specially crafted URL.

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2021-20875"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-601"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2021-12-24T07:15:00Z",
    "severity": "MODERATE"
  },
  "details": "Open redirect vulnerability in GroupSession Free edition ver5.1.1 and earlier, GroupSession byCloud ver5.1.1 and earlier, and GroupSession ZION ver5.1.1 and earlier allows a remote unauthenticated attacker to redirect users to arbitrary web sites and conduct phishing attacks by having a user to access a specially crafted URL.",
  "id": "GHSA-vj52-jgg8-wg96",
  "modified": "2022-01-11T00:02:14Z",
  "published": "2021-12-25T00:00:29Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2021-20875"
    },
    {
      "type": "WEB",
      "url": "https://groupsession.jp/info/info-news/security20211220"
    },
    {
      "type": "WEB",
      "url": "https://jvn.jp/en/jp/JVN79798166/index.html"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

GHSA-VJG6-28MM-FV75

Vulnerability from github – Published: 2022-05-24 19:19 – Updated: 2022-05-24 19:19
VLAI
Details

An open redirect vulnerability exists in Replicated Classic versions prior to 2.53.1 that could lead to spoofing. To exploit this vulnerability, an attacker could send a link that has a specially crafted URL and convince the user to click the link, redirecting the user to an untrusted site.

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2021-43058"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-601"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2021-11-01T22:15:00Z",
    "severity": "MODERATE"
  },
  "details": "An open redirect vulnerability exists in Replicated Classic versions prior to 2.53.1 that could lead to spoofing. To exploit this vulnerability, an attacker could send a link that has a specially crafted URL and convince the user to click the link, redirecting the user to an untrusted site.",
  "id": "GHSA-vjg6-28mm-fv75",
  "modified": "2022-05-24T19:19:30Z",
  "published": "2022-05-24T19:19:30Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2021-43058"
    },
    {
      "type": "WEB",
      "url": "https://www.replicated.com/security/advisories/CVE-2021-43058"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

GHSA-VJX7-HF5R-CHV4

Vulnerability from github – Published: 2024-06-24 06:30 – Updated: 2024-12-04 21:30
VLAI
Details

The SEOPress WordPress plugin before 7.8 does not validate and escape one of its Post settings, which could allow contributor and above role to perform Open redirect attacks against any user viewing a malicious post

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2024-4900"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-601"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2024-06-24T06:15:11Z",
    "severity": "MODERATE"
  },
  "details": "The SEOPress  WordPress plugin before 7.8 does not validate and escape one of its Post settings, which could allow contributor and above role to perform Open redirect attacks against any user viewing a malicious post",
  "id": "GHSA-vjx7-hf5r-chv4",
  "modified": "2024-12-04T21:30:51Z",
  "published": "2024-06-24T06:30:55Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2024-4900"
    },
    {
      "type": "WEB",
      "url": "https://wpscan.com/vulnerability/a56ad272-e2ed-4064-9b5d-114a834dd8b3"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-VM5J-X654-R2WW

Vulnerability from github – Published: 2022-05-24 16:44 – Updated: 2026-06-03 15:30
VLAI
Details

In Rockwell Automation MicroLogix 1400 Controllers Series A, All Versions Series B, v15.002 and earlier, MicroLogix 1100 Controllers v14.00 and earlier, CompactLogix 5370 L1 controllers v30.014 and earlier, CompactLogix 5370 L2 controllers v30.014 and earlier, CompactLogix 5370 L3 controllers (includes CompactLogix GuardLogix controllers) v30.014 and earlier, an open redirect vulnerability could allow a remote unauthenticated attacker to input a malicious link to redirect users to a malicious site that could run or download arbitrary malware on the user?s machine.

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2019-10955"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-601"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2019-04-25T18:29:00Z",
    "severity": "MODERATE"
  },
  "details": "In Rockwell Automation MicroLogix 1400 Controllers Series A, All Versions Series B, v15.002 and earlier, MicroLogix 1100 Controllers v14.00 and earlier, CompactLogix 5370 L1 controllers v30.014 and earlier, CompactLogix 5370 L2 controllers v30.014 and earlier, CompactLogix 5370 L3 controllers (includes CompactLogix GuardLogix controllers) v30.014 and earlier, an open redirect vulnerability could allow a remote unauthenticated attacker to input a malicious link to redirect users to a malicious site that could run or download arbitrary malware on the user?s machine.",
  "id": "GHSA-vm5j-x654-r2ww",
  "modified": "2026-06-03T15:30:33Z",
  "published": "2022-05-24T16:44:41Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2019-10955"
    },
    {
      "type": "WEB",
      "url": "https://ics-cert.us-cert.gov/advisories/ICSA-19-113-01"
    },
    {
      "type": "WEB",
      "url": "https://www.securityfocus.com/bid/108049"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-VP58-J275-797X

Vulnerability from github – Published: 2025-02-24 20:49 – Updated: 2025-12-09 16:27
VLAI
Summary
Better Auth allows bypassing the trustedOrigins Protection which leads to ATO
Details

Summary

A bypass was discovered in the trustedOrigins validation logic—affecting both absolute URL entries and wildcard domain patterns. This flaw allows an attacker to construct a malicious callbackURL that passes origin checks and triggers an open redirect.

Because redirect endpoints include sensitive tokens (such as password-reset tokens), this vulnerability can enable one-click account takeover if a victim clicks a crafted link.

Show details on source website

{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 1.1.20"
      },
      "package": {
        "ecosystem": "npm",
        "name": "better-auth"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.1.21"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [],
  "database_specific": {
    "cwe_ids": [
      "CWE-601"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2025-02-24T20:49:50Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "### Summary\n\nA bypass was discovered in the trustedOrigins validation logic\u2014affecting both absolute URL entries and wildcard domain patterns. This flaw allows an attacker to construct a malicious callbackURL that passes origin checks and triggers an open redirect.\n\nBecause redirect endpoints include sensitive tokens (such as password-reset tokens), this vulnerability can enable one-click account takeover if a victim clicks a crafted link.",
  "id": "GHSA-vp58-j275-797x",
  "modified": "2025-12-09T16:27:07Z",
  "published": "2025-02-24T20:49:50Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/better-auth/better-auth/security/advisories/GHSA-vp58-j275-797x"
    },
    {
      "type": "WEB",
      "url": "https://github.com/better-auth/better-auth/commit/b381cac7aafd6aa53ef78b6ab771ebfa24643c80"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/better-auth/better-auth"
    },
    {
      "type": "WEB",
      "url": "https://github.com/better-auth/better-auth/blob/ddebd0358d74376ea64541512d0167dd4377f182/packages/better-auth/src/api/middlewares/origin-check.ts#L53"
    }
  ],
  "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:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Better Auth allows bypassing the trustedOrigins Protection which leads to ATO"
}

GHSA-VP8J-FQ8W-QWPR

Vulnerability from github – Published: 2026-09-08 21:34 – Updated: 2026-09-10 18:31
VLAI
Details

In onCreate of InstallLaunch.kt, there is a possible misleading UI due to a tapjacking/overlay attack. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2026-28572"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-601"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-08T19:17:51Z",
    "severity": "HIGH"
  },
  "details": "In onCreate of InstallLaunch.kt, there is a possible misleading UI due to a tapjacking/overlay attack. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.",
  "id": "GHSA-vp8j-fq8w-qwpr",
  "modified": "2026-09-10T18:31:32Z",
  "published": "2026-09-08T21:34:14Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-28572"
    },
    {
      "type": "WEB",
      "url": "https://source.android.com/docs/security/bulletin/2026/2026-09-01"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-VP8P-C6XJ-XPJ7

Vulnerability from github – Published: 2024-05-23 17:12 – Updated: 2024-05-23 17:12
VLAI
Summary
Silverstripe External redirection risk in Security?ReturnURL
Details

A vulnerability has been found in the SilverStripe framework where a login url can be potentially redirected to an external site.

For example, the url http://www.my-silverstripe-site.com/Security/login?BackURL=/\attacker-site.com will redirect successful logins to the page http://attacker-site.com. If that website were set up to look identical to the first with "login failed" then the user will likely just enter their user/pass again.

Show details on source website

{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 3.0.13"
      },
      "package": {
        "ecosystem": "Packagist",
        "name": "silverstripe/framework"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.0.14"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 3.1.13-rc1"
      },
      "package": {
        "ecosystem": "Packagist",
        "name": "silverstripe/framework"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "3.1.0"
            },
            {
              "fixed": "3.1.13"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [],
  "database_specific": {
    "cwe_ids": [
      "CWE-601"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2024-05-23T17:12:13Z",
    "nvd_published_at": null,
    "severity": "MODERATE"
  },
  "details": "A vulnerability has been found in the SilverStripe framework where a login url can be potentially redirected to an external site.\n\nFor example, the url http://www.my-silverstripe-site.com/Security/login?BackURL=/\\attacker-site.com will redirect successful logins to the page http://attacker-site.com. If that website were set up to look identical to the first with \"login failed\" then the user will likely just enter their user/pass again.",
  "id": "GHSA-vp8p-c6xj-xpj7",
  "modified": "2024-05-23T17:12:13Z",
  "published": "2024-05-23T17:12:13Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/silverstripe/silverstripe-framework/commit/22a35e48a9f513d4caa3b4e9b8dd21c49ffc8f2c"
    },
    {
      "type": "WEB",
      "url": "https://github.com/silverstripe/silverstripe-framework/commit/c14e7f6b764ae4646461f3fc3a46452fdaa9e02a"
    },
    {
      "type": "WEB",
      "url": "https://github.com/FriendsOfPHP/security-advisories/blob/master/silverstripe/framework/SS-2015-012-1.yaml"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/silverstripe/silverstripe-framework"
    },
    {
      "type": "WEB",
      "url": "https://www.silverstripe.org/software/download/security-releases/ss-2015-012"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Silverstripe External redirection risk in Security?ReturnURL"
}

Mitigation MIT-5
Implementation

Strategy: Input Validation

  • Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
  • When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, "boat" may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as "red" or "blue."
  • Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code's environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.
  • Use a list of approved URLs or domains to be used for redirection.
Mitigation
Architecture and Design

Use an intermediate disclaimer page that provides the user with a clear warning that they are leaving the current site. Implement a long timeout before the redirect occurs, or force the user to click on the link. Be careful to avoid XSS problems (CWE-79) when generating the disclaimer page.

Mitigation MIT-21.2
Architecture and Design

Strategy: Enforcement by Conversion

  • When the set of acceptable objects, such as filenames or URLs, is limited or known, create a mapping from a set of fixed input values (such as numeric IDs) to the actual filenames or URLs, and reject all other inputs.
  • For example, ID 1 could map to "/login.asp" and ID 2 could map to "http://www.example.com/". Features such as the ESAPI AccessReferenceMap [REF-45] provide this capability.
Mitigation
Architecture and Design

Ensure that no externally-supplied requests are honored by requiring that all redirect requests include a unique nonce generated by the application [REF-483]. Be sure that the nonce is not predictable (CWE-330).

Mitigation MIT-6
Architecture and Design Implementation

Strategy: Attack Surface Reduction

  • Understand all the potential areas where untrusted inputs can enter your software: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any external systems that provide data to the application. Remember that such inputs may be obtained indirectly through API calls.
  • Many open redirect problems occur because the programmer assumed that certain inputs could not be modified, such as cookies and hidden form fields.
Mitigation MIT-29
Operation

Strategy: Firewall

Use an application firewall that can detect attacks against this weakness. It can be beneficial in cases in which the code cannot be fixed (because it is controlled by a third party), as an emergency prevention measure while more comprehensive software assurance measures are applied, or to provide defense in depth [REF-1481].

CAPEC-178: Cross-Site Flashing

An attacker is able to trick the victim into executing a Flash document that passes commands or calls to a Flash player browser plugin, allowing the attacker to exploit native Flash functionality in the client browser. This attack pattern occurs where an attacker can provide a crafted link to a Flash document (SWF file) which, when followed, will cause additional malicious instructions to be executed. The attacker does not need to serve or control the Flash document. The attack takes advantage of the fact that Flash files can reference external URLs. If variables that serve as URLs that the Flash application references can be controlled through parameters, then by creating a link that includes values for those parameters, an attacker can cause arbitrary content to be referenced and possibly executed by the targeted Flash application.