CWE-601
AllowedURL 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.
2575 vulnerabilities reference this CWE, most recent first.
GHSA-HRR3-4MF8-J2W9
Vulnerability from github – Published: 2022-05-14 03:01 – Updated: 2022-05-14 03:01Redirection version 2.7.3 contains a ACE via file inclusion vulnerability in Pass-through mode that can result in allows admins to execute any PHP file in the filesystem. This attack appear to be exploitable via Attacker must be have access to an admin account on the target site. This vulnerability appears to have been fixed in 2.8.
{
"affected": [],
"aliases": [
"CVE-2018-1000504"
],
"database_specific": {
"cwe_ids": [
"CWE-601"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2018-06-26T16:29:00Z",
"severity": "HIGH"
},
"details": "Redirection version 2.7.3 contains a ACE via file inclusion vulnerability in Pass-through mode that can result in allows admins to execute any PHP file in the filesystem. This attack appear to be exploitable via Attacker must be have access to an admin account on the target site. This vulnerability appears to have been fixed in 2.8.",
"id": "GHSA-hrr3-4mf8-j2w9",
"modified": "2022-05-14T03:01:31Z",
"published": "2022-05-14T03:01:31Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2018-1000504"
},
{
"type": "WEB",
"url": "https://advisories.dxw.com/advisories/ace-file-inclusion-redirection"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
GHSA-HRVR-J498-5VHH
Vulnerability from github – Published: 2026-04-01 03:31 – Updated: 2026-04-01 03:31XenForo before 2.2.17 and 2.3.1 allows open redirect via a specially crafted URL. The getDynamicRedirect() function does not adequately validate the redirect target, allowing attackers to redirect users to arbitrary external sites using crafted URLs containing newlines, user credentials, or host mismatches.
{
"affected": [],
"aliases": [
"CVE-2024-58342"
],
"database_specific": {
"cwe_ids": [
"CWE-601"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-04-01T01:16:39Z",
"severity": "MODERATE"
},
"details": "XenForo before 2.2.17 and 2.3.1 allows open redirect via a specially crafted URL. The getDynamicRedirect() function does not adequately validate the redirect target, allowing attackers to redirect users to arbitrary external sites using crafted URLs containing newlines, user credentials, or host mismatches.",
"id": "GHSA-hrvr-j498-5vhh",
"modified": "2026-04-01T03:31:40Z",
"published": "2026-04-01T03:31:40Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-58342"
},
{
"type": "WEB",
"url": "https://www.vulncheck.com/advisories/xenforo-open-redirect-via-getdynamicredirect"
},
{
"type": "WEB",
"url": "https://xenforo.com/community/threads/xenforo-2-2-17-released-security-fix.227797"
}
],
"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:L",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
"type": "CVSS_V4"
}
]
}
GHSA-HVPP-QRXV-C9G3
Vulnerability from github – Published: 2022-04-14 00:00 – Updated: 2022-04-21 00:00An open redirect vulnerability in Hubzilla before version 7.2 allows remote attackers to redirect a logged in user to an arbitrary URL via the rpath parameter.
{
"affected": [],
"aliases": [
"CVE-2022-27256"
],
"database_specific": {
"cwe_ids": [
"CWE-601"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2022-04-13T14:15:00Z",
"severity": "MODERATE"
},
"details": "An open redirect vulnerability in Hubzilla before version 7.2 allows remote attackers to redirect a logged in user to an arbitrary URL via the rpath parameter.",
"id": "GHSA-hvpp-qrxv-c9g3",
"modified": "2022-04-21T00:00:39Z",
"published": "2022-04-14T00:00:18Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2022-27256"
},
{
"type": "WEB",
"url": "https://framagit.org/hubzilla/core/-/commit/0784cd593a39a4fc297e8a82f7e79bc8019a0868#1c497fbb3a46b78edf04cc2a2fa33f67e3ffbe2a"
},
{
"type": "WEB",
"url": "https://hubzilla.org/channel/hubzilla"
},
{
"type": "WEB",
"url": "https://volse.net/~haraldei/infosec/disclosures/hubzilla-before-7-2-multiple-vulnerabilities"
}
],
"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-HVQ6-F5P6-23F6
Vulnerability from github – Published: 2026-07-29 21:31 – Updated: 2026-07-29 21:31Dify AI Workflow oauth_redirect_url Open Redirect Vulnerability. This vulnerability allows remote attackers to disclose sensitive information on affected installations of Dify. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file.
The specific flaw exists within the OAuth flow handling in the AppInitializer component. An attacker can force a redirection to a site that serves malicious content. An attacker can leverage this vulnerability to disclose information in the context of the application. Was ZDI-CAN-29196.
{
"affected": [],
"aliases": [
"CVE-2026-18266"
],
"database_specific": {
"cwe_ids": [
"CWE-601"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-07-29T20:17:02Z",
"severity": "MODERATE"
},
"details": "Dify AI Workflow oauth_redirect_url Open Redirect Vulnerability. This vulnerability allows remote attackers to disclose sensitive information on affected installations of Dify. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file.\n\nThe specific flaw exists within the OAuth flow handling in the AppInitializer component. An attacker can force a redirection to a site that serves malicious content. An attacker can leverage this vulnerability to disclose information in the context of the application. Was ZDI-CAN-29196.",
"id": "GHSA-hvq6-f5p6-23f6",
"modified": "2026-07-29T21:31:00Z",
"published": "2026-07-29T21:31:00Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-18266"
},
{
"type": "WEB",
"url": "https://www.zerodayinitiative.com/advisories/ZDI-26-452"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-HVRR-JRCJ-QQP5
Vulnerability from github – Published: 2026-08-31 15:34 – Updated: 2026-08-31 15:34Joomla Extension - joomshaper.com - Open Redirect via Base64 Return Parameter in Helix Ultimate < 2.2.10 - Return redirect parameters accepted arbitrary Base64 strings without verifying whether the resolved target was an internal site URL via Uri::isInternal.
{
"affected": [],
"aliases": [
"CVE-2026-78079"
],
"database_specific": {
"cwe_ids": [
"CWE-601"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-08-31T14:17:24Z",
"severity": "MODERATE"
},
"details": "Joomla Extension - joomshaper.com - Open Redirect via Base64 Return Parameter in Helix Ultimate \u003c 2.2.10 - Return redirect parameters accepted arbitrary Base64 strings without verifying whether the resolved target was an internal site URL via Uri::isInternal.",
"id": "GHSA-hvrr-jrcj-qqp5",
"modified": "2026-08-31T15:34:45Z",
"published": "2026-08-31T15:34:45Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-78079"
},
{
"type": "WEB",
"url": "https://www.joomshaper.com/joomla-templates/helixultimate"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
"type": "CVSS_V4"
}
]
}
GHSA-HVW3-P9PX-GPC9
Vulnerability from github – Published: 2022-09-12 00:00 – Updated: 2022-09-16 22:02This affects the package github.com/gophish/gophish before 0.12.0. The Open Redirect vulnerability exists in the next query parameter. The application uses url.Parse(r.FormValue("next")) to extract path and eventually redirect user to a relative URL, but if next parameter starts with multiple backslashes like \\\example.com, browser will redirect user to http://example.com.
{
"affected": [
{
"package": {
"ecosystem": "Go",
"name": "github.com/gophish/gophish"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "0.12.0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2022-25295"
],
"database_specific": {
"cwe_ids": [
"CWE-601"
],
"github_reviewed": true,
"github_reviewed_at": "2022-09-15T03:28:46Z",
"nvd_published_at": "2022-09-11T14:15:00Z",
"severity": "MODERATE"
},
"details": "This affects the package github.com/gophish/gophish before 0.12.0. The Open Redirect vulnerability exists in the next query parameter. The application uses url.Parse(r.FormValue(\"next\")) to extract path and eventually redirect user to a relative URL, but if next parameter starts with multiple backslashes like \\\\\\\\\\\\example.com, browser will redirect user to http://example.com.",
"id": "GHSA-hvw3-p9px-gpc9",
"modified": "2022-09-16T22:02:43Z",
"published": "2022-09-12T00:00:33Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2022-25295"
},
{
"type": "WEB",
"url": "https://github.com/gophish/gophish/pull/2262"
},
{
"type": "WEB",
"url": "https://github.com/gophish/gophish/commit/2a452bda89ffdb85f929fa78290bce1f456881dc"
},
{
"type": "PACKAGE",
"url": "https://github.com/gophish/gophish"
},
{
"type": "WEB",
"url": "https://github.com/gophish/gophish/releases/tag/v0.12.0"
},
{
"type": "WEB",
"url": "https://security.snyk.io/vuln/SNYK-GOLANG-GITHUBCOMGOPHISHGOPHISH-2404177"
}
],
"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"
}
],
"summary": "Gophish before 0.12.0 vulnerable to Open Redirect"
}
GHSA-HW22-25CV-28G5
Vulnerability from github – Published: 2026-09-16 03:31 – Updated: 2026-09-16 03:31A vulnerability was found in a2ui-project a2ui up to 0.10.7. Affected by this issue is the function openUrl of the file renderers/web_core/src/v0_9/rendering/generic-binder.ts of the component Binder. The manipulation results in open redirect. It is possible to launch the attack remotely. The project was informed of the problem early through an issue report but has not responded yet.
{
"affected": [],
"aliases": [
"CVE-2026-92216"
],
"database_specific": {
"cwe_ids": [
"CWE-601"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-09-16T02:17:38Z",
"severity": "MODERATE"
},
"details": "A vulnerability was found in a2ui-project a2ui up to 0.10.7. Affected by this issue is the function openUrl of the file renderers/web_core/src/v0_9/rendering/generic-binder.ts of the component Binder. The manipulation results in open redirect. It is possible to launch the attack remotely. The project was informed of the problem early through an issue report but has not responded yet.",
"id": "GHSA-hw22-25cv-28g5",
"modified": "2026-09-16T03:31:09Z",
"published": "2026-09-16T03:31:09Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-92216"
},
{
"type": "WEB",
"url": "https://github.com/a2ui-project/a2ui/issues/2296"
},
{
"type": "WEB",
"url": "https://github.com/a2ui-project/a2ui"
},
{
"type": "WEB",
"url": "https://vuldb.com/cve/CVE-2026-92216"
},
{
"type": "WEB",
"url": "https://vuldb.com/submit/934110"
},
{
"type": "WEB",
"url": "https://vuldb.com/vuln/404461"
},
{
"type": "WEB",
"url": "https://vuldb.com/vuln/404461/cti"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/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-HW32-H72W-XCX4
Vulnerability from github – Published: 2022-05-24 16:49 – Updated: 2024-04-04 01:11An issue was discovered in Eventum 3.5.0. /htdocs/switch.php has an Open Redirect via the current_page parameter.
{
"affected": [],
"aliases": [
"CVE-2018-12621"
],
"database_specific": {
"cwe_ids": [
"CWE-601"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2019-07-05T17:15:00Z",
"severity": "MODERATE"
},
"details": "An issue was discovered in Eventum 3.5.0. /htdocs/switch.php has an Open Redirect via the current_page parameter.",
"id": "GHSA-hw32-h72w-xcx4",
"modified": "2024-04-04T01:11:46Z",
"published": "2022-05-24T16:49:33Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2018-12621"
},
{
"type": "WEB",
"url": "https://github.com/eventum/eventum/blob/master/CHANGELOG.md"
},
{
"type": "WEB",
"url": "https://github.com/eventum/eventum/releases/tag/v3.5.2"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-HW3M-8J5X-94FF
Vulnerability from github – Published: 2026-09-18 16:51 – Updated: 2026-09-18 16:51Failure mode
Special:URIResolver resolves its user-controlled subpage to a MediaWiki title and issues an HTTP 303 redirect to $title->getFullURL() without validating the resolved target. A crafted subpage can make that target point off-host: an interwiki prefix redirects to the foreign wiki (for example Special:URIResolver/mw-3AFoo, which decodes to mw:Foo, redirects to https://www.mediawiki.org/wiki/Foo), and where the resolved URL carries an authority the target can even embed user:pass@host credentials. The result is an open redirect to an attacker-influenced host, usable for phishing from a trusted wiki URL.
Remediation
- The resolved target URL is parsed and compared against the current host at the redirect sink.
- The redirect is rejected (bad-title error page) when a user or pass component is present, or when the host does not match the current host.
Maintenance note
Redirect code must validate the final target URL, not just the input path. Host comparison belongs at the redirect sink: each sink (special page, entry point) must validate its own target rather than relying on upstream normalisation.
{
"affected": [
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 7.1.0"
},
"package": {
"ecosystem": "Packagist",
"name": "mediawiki/semantic-media-wiki"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "7.2.0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-77609"
],
"database_specific": {
"cwe_ids": [
"CWE-601"
],
"github_reviewed": true,
"github_reviewed_at": "2026-09-18T16:51:25Z",
"nvd_published_at": null,
"severity": "MODERATE"
},
"details": "#### Failure mode\n\n`Special:URIResolver` resolves its user-controlled subpage to a MediaWiki title and issues an HTTP 303 redirect to `$title-\u003egetFullURL()` without validating the resolved target. A crafted subpage can make that target point off-host: an interwiki prefix redirects to the foreign wiki (for example `Special:URIResolver/mw-3AFoo`, which decodes to `mw:Foo`, redirects to `https://www.mediawiki.org/wiki/Foo`), and where the resolved URL carries an authority the target can even embed `user:pass@host` credentials. The result is an open redirect to an attacker-influenced host, usable for phishing from a trusted wiki URL.\n\n#### Remediation\n\n- The resolved target URL is parsed and compared against the current host at the redirect sink.\n- The redirect is rejected (bad-title error page) when a user or pass component is present, or when the host does not match the current host.\n\n#### Maintenance note\n\nRedirect code must validate the final target URL, not just the input path. Host comparison belongs at the redirect sink: each sink (special page, entry point) must validate its own target rather than relying on upstream normalisation.",
"id": "GHSA-hw3m-8j5x-94ff",
"modified": "2026-09-18T16:51:25Z",
"published": "2026-09-18T16:51:25Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/SemanticMediaWiki/SemanticMediaWiki/security/advisories/GHSA-hw3m-8j5x-94ff"
},
{
"type": "PACKAGE",
"url": "https://github.com/SemanticMediaWiki/SemanticMediaWiki"
},
{
"type": "WEB",
"url": "https://github.com/SemanticMediaWiki/SemanticMediaWiki/releases/tag/7.2.0"
}
],
"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"
}
],
"summary": "Semantic MediaWiki has an open redirect in Special:URIResolver"
}
GHSA-HW84-C76J-H87P
Vulnerability from github – Published: 2024-05-14 18:31 – Updated: 2026-04-08 18:33The WP Compress – Image Optimizer [All-In-One] plugin for WordPress is vulnerable to unauthorized modification of data due to a missing capability check on the several functions in versions up to, and including, 6.20.01. This makes it possible for authenticated attackers, with subscriber-level permissions and above, to edit plugin settings, including storing cross-site scripting, in multisite environments.
{
"affected": [],
"aliases": [
"CVE-2024-4445"
],
"database_specific": {
"cwe_ids": [
"CWE-601",
"CWE-862"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-05-14T16:17:34Z",
"severity": "MODERATE"
},
"details": "The WP Compress \u2013 Image Optimizer [All-In-One] plugin for WordPress is vulnerable to unauthorized modification of data due to a missing capability check on the several functions in versions up to, and including, 6.20.01. This makes it possible for authenticated attackers, with subscriber-level permissions and above, to edit plugin settings, including storing cross-site scripting, in multisite environments.",
"id": "GHSA-hw84-c76j-h87p",
"modified": "2026-04-08T18:33:12Z",
"published": "2024-05-14T18:31:02Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-4445"
},
{
"type": "WEB",
"url": "https://plugins.trac.wordpress.org/browser/wp-compress-image-optimizer/trunk/classes/mu.class.php?rev=2946135"
},
{
"type": "WEB",
"url": "https://plugins.trac.wordpress.org/changeset/3082085/#file655"
},
{
"type": "WEB",
"url": "https://www.wordfence.com/threat-intel/vulnerabilities/id/830f53a4-da3b-4a95-99f1-c4a4c8e6944c?source=cve"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N",
"type": "CVSS_V3"
}
]
}
Mitigation MIT-5
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
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
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
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
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
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.