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.
2334 vulnerabilities reference this CWE, most recent first.
GHSA-8CG9-5V35-372M
Vulnerability from github – Published: 2023-01-12 06:30 – Updated: 2023-01-20 21:30An issue has been discovered in GitLab CE/EE affecting all versions starting from 11.4 prior to 15.5.7, 15.6 prior to 15.6.4, and 15.7 prior to 15.7.2. GitLab Pages allows redirection to arbitrary protocols.
{
"affected": [],
"aliases": [
"CVE-2023-0042"
],
"database_specific": {
"cwe_ids": [
"CWE-601"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2023-01-12T04:15:00Z",
"severity": "MODERATE"
},
"details": "An issue has been discovered in GitLab CE/EE affecting all versions starting from 11.4 prior to 15.5.7, 15.6 prior to 15.6.4, and 15.7 prior to 15.7.2. GitLab Pages allows redirection to arbitrary protocols.",
"id": "GHSA-8cg9-5v35-372m",
"modified": "2023-01-20T21:30:29Z",
"published": "2023-01-12T06:30:24Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-0042"
},
{
"type": "WEB",
"url": "https://gitlab.com/gitlab-org/cves/-/blob/master/2023/CVE-2023-0042.json"
},
{
"type": "WEB",
"url": "https://gitlab.com/gitlab-org/gitlab-pages/-/issues/728"
}
],
"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-8F24-V5VV-GM5J
Vulnerability from github – Published: 2026-04-10 21:03 – Updated: 2026-04-24 20:48Impact
Applications using the next-intl middleware with localePrefix: 'as-needed' could construct URLs where path handling and the WHATWG URL parser resolved a relative redirect target to another host (e.g. scheme-relative // or control characters stripped by the URL parser), so the middleware could redirect the browser off-site while the user still started from a trusted app URL.
Patches
The problem has been patched, please update to next-intl@4.9.1.
Credits
Many thanks to Joni Liljeblad from Oura for responsibly disclosing the vulnerability and for suggesting the fix.
{
"affected": [
{
"package": {
"ecosystem": "npm",
"name": "next-intl"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "4.9.1"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-40299"
],
"database_specific": {
"cwe_ids": [
"CWE-601"
],
"github_reviewed": true,
"github_reviewed_at": "2026-04-10T21:03:55Z",
"nvd_published_at": "2026-04-17T21:16:34Z",
"severity": "MODERATE"
},
"details": "### Impact\n\nApplications using the `next-intl` middleware with `localePrefix: \u0027as-needed\u0027` could construct URLs where path handling and the WHATWG URL parser resolved a relative redirect target to another host (e.g. scheme-relative `//` or control characters stripped by the URL parser), so the middleware could redirect the browser off-site while the user still started from a trusted app URL.\n\n### Patches\n\nThe problem has been patched, please update to [`next-intl@4.9.1`](https://github.com/amannn/next-intl/releases/tag/v4.9.1).\n\n### Credits\n\nMany thanks to [Joni Liljeblad](https://github.com/joniumGit) from [Oura](https://ouraring.com) for responsibly disclosing the vulnerability and for suggesting the fix.",
"id": "GHSA-8f24-v5vv-gm5j",
"modified": "2026-04-24T20:48:37Z",
"published": "2026-04-10T21:03:55Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/amannn/next-intl/security/advisories/GHSA-8f24-v5vv-gm5j"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-40299"
},
{
"type": "WEB",
"url": "https://github.com/amannn/next-intl/pull/2304"
},
{
"type": "WEB",
"url": "https://github.com/amannn/next-intl/commit/1c80b668aa6d853f470319eec10a3f61e78a70e6"
},
{
"type": "PACKAGE",
"url": "https://github.com/amannn/next-intl"
},
{
"type": "WEB",
"url": "https://github.com/amannn/next-intl/releases/tag/v4.9.1"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N",
"type": "CVSS_V4"
}
],
"summary": "next-intl has an open redirect vulnerability"
}
GHSA-8F7C-VCGW-5JMM
Vulnerability from github – Published: 2023-12-19 21:32 – Updated: 2026-04-28 21:33URL Redirection to Untrusted Site ('Open Redirect') vulnerability in Swapnil V. Patil Login and Logout Redirect.This issue affects Login and Logout Redirect: from n/a through 2.0.3.
{
"affected": [],
"aliases": [
"CVE-2023-41648"
],
"database_specific": {
"cwe_ids": [
"CWE-601"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2023-12-19T20:15:08Z",
"severity": "MODERATE"
},
"details": "URL Redirection to Untrusted Site (\u0027Open Redirect\u0027) vulnerability in Swapnil V. Patil Login and Logout Redirect.This issue affects Login and Logout Redirect: from n/a through 2.0.3.",
"id": "GHSA-8f7c-vcgw-5jmm",
"modified": "2026-04-28T21:33:26Z",
"published": "2023-12-19T21:32:20Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-41648"
},
{
"type": "WEB",
"url": "https://patchstack.com/database/vulnerability/login-and-logout-redirect/wordpress-login-and-logout-redirect-plugin-2-0-2-open-redirection-vulnerability?_s_id=cve"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:N/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-8FFF-XG97-GQ6F
Vulnerability from github – Published: 2022-05-14 03:19 – Updated: 2022-05-14 03:19RSA Authentication Manager Security Console, Operation Console and Self-Service Console, version 8.3 and earlier, is affected by a Host header injection vulnerability. This could allow a remote attacker to potentially poison HTTP cache and subsequently redirect users to arbitrary web domains.
{
"affected": [],
"aliases": [
"CVE-2018-1248"
],
"database_specific": {
"cwe_ids": [
"CWE-601"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2018-05-08T13:29:00Z",
"severity": "MODERATE"
},
"details": "RSA Authentication Manager Security Console, Operation Console and Self-Service Console, version 8.3 and earlier, is affected by a Host header injection vulnerability. This could allow a remote attacker to potentially poison HTTP cache and subsequently redirect users to arbitrary web domains.",
"id": "GHSA-8fff-xg97-gq6f",
"modified": "2022-05-14T03:19:06Z",
"published": "2022-05-14T03:19:06Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2018-1248"
},
{
"type": "WEB",
"url": "http://seclists.org/fulldisclosure/2018/May/18"
},
{
"type": "WEB",
"url": "http://www.securityfocus.com/bid/104113"
},
{
"type": "WEB",
"url": "http://www.securitytracker.com/id/1040835"
}
],
"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-8FHH-33X2-C7C5
Vulnerability from github – Published: 2026-04-10 18:31 – Updated: 2026-04-14 21:31An open redirect vulnerability in Rocket.Chat versions prior to 8.4.0 allows users to be redirected to arbitrary URLs by manipulating parameters within a SAML endpoint.
{
"affected": [],
"aliases": [
"CVE-2026-22560"
],
"database_specific": {
"cwe_ids": [
"CWE-601"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-04-10T17:17:01Z",
"severity": "MODERATE"
},
"details": "An open redirect vulnerability in Rocket.Chat versions prior to 8.4.0 allows users to be redirected to arbitrary URLs by manipulating parameters within a SAML endpoint.",
"id": "GHSA-8fhh-33x2-c7c5",
"modified": "2026-04-14T21:31:44Z",
"published": "2026-04-10T18:31:18Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-22560"
},
{
"type": "WEB",
"url": "https://github.com/RocketChat/Rocket.Chat/pull/38994"
},
{
"type": "WEB",
"url": "https://hackerone.com/reports/3418031"
}
],
"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:L",
"type": "CVSS_V3"
}
]
}
GHSA-8FP2-92VW-8CPC
Vulnerability from github – Published: 2026-05-14 18:32 – Updated: 2026-05-14 18:32CWE-601 URL redirection to untrusted site ('open redirect')
{
"affected": [],
"aliases": [
"CVE-2026-45448"
],
"database_specific": {
"cwe_ids": [
"CWE-601"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-05-14T17:16:23Z",
"severity": "MODERATE"
},
"details": "CWE-601 URL redirection to untrusted site (\u0027open redirect\u0027)",
"id": "GHSA-8fp2-92vw-8cpc",
"modified": "2026-05-14T18:32:57Z",
"published": "2026-05-14T18:32:57Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-45448"
},
{
"type": "WEB",
"url": "https://www.gov.il/en/departments/dynamiccollectors/cve_advisories_listing?skip=0"
}
],
"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:N",
"type": "CVSS_V3"
}
]
}
GHSA-8FR3-HFG3-GPGP
Vulnerability from github – Published: 2022-01-21 23:36 – Updated: 2023-09-11 22:42parseUrl functionality in node-forge mishandles certain uses of backslash such as https:/\/\/\ and interprets the URI as a relative path.
{
"affected": [
{
"package": {
"ecosystem": "npm",
"name": "node-forge"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "1.0.0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2022-0122"
],
"database_specific": {
"cwe_ids": [
"CWE-601"
],
"github_reviewed": true,
"github_reviewed_at": "2022-01-13T18:49:59Z",
"nvd_published_at": "2022-01-06T05:15:00Z",
"severity": "MODERATE"
},
"details": "parseUrl functionality in node-forge mishandles certain uses of backslash such as `https:/\\/\\/\\` and interprets the URI as a relative path. ",
"id": "GHSA-8fr3-hfg3-gpgp",
"modified": "2023-09-11T22:42:40Z",
"published": "2022-01-21T23:36:19Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2022-0122"
},
{
"type": "WEB",
"url": "https://github.com/digitalbazaar/forge/commit/db8016c805371e72b06d8e2edfe0ace0df934a5e"
},
{
"type": "PACKAGE",
"url": "https://github.com/digitalbazaar/forge"
},
{
"type": "WEB",
"url": "https://huntr.dev/bounties/41852c50-3c6d-4703-8c55-4db27164a4ae"
}
],
"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": "Open Redirect in node-forge"
}
GHSA-8G72-GQ68-6GQH
Vulnerability from github – Published: 2022-05-14 03:49 – Updated: 2024-10-17 20:58When you visit a page where you need to login, Plone 2.5-5.1rc1 sends you to the login form with a 'came_from' parameter set to the previous url. After you login, you get redirected to the page you tried to view before. An attacker might try to abuse this by letting you click on a specially crafted link. You would login, and get redirected to the site of the attacker, letting you think that you are still on the original Plone site. Or some javascript of the attacker could be executed. Most of these types of attacks are already blocked by Plone, using the isURLInPortal check to make sure we only redirect to a page on the same Plone site. But a few more ways of tricking Plone into accepting a malicious link were discovered, and fixed with this hotfix.
{
"affected": [
{
"package": {
"ecosystem": "PyPI",
"name": "Products.CMFPlone"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "4.3.17"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "PyPI",
"name": "Products.CMFPlone"
},
"ranges": [
{
"events": [
{
"introduced": "5.0.0"
},
{
"fixed": "5.0.10"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "PyPI",
"name": "Products.CMFPlone"
},
"ranges": [
{
"events": [
{
"introduced": "5.1a1"
},
{
"fixed": "5.1.0"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "PyPI",
"name": "Plone"
},
"ranges": [
{
"events": [
{
"introduced": "2.5"
},
{
"fixed": "4.3.16"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "PyPI",
"name": "Plone"
},
"ranges": [
{
"events": [
{
"introduced": "5"
},
{
"fixed": "5.1.0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2017-1000481"
],
"database_specific": {
"cwe_ids": [
"CWE-601"
],
"github_reviewed": true,
"github_reviewed_at": "2023-07-26T21:54:46Z",
"nvd_published_at": "2018-01-03T18:29:00Z",
"severity": "MODERATE"
},
"details": "When you visit a page where you need to login, Plone 2.5-5.1rc1 sends you to the login form with a \u0027came_from\u0027 parameter set to the previous url. After you login, you get redirected to the page you tried to view before. An attacker might try to abuse this by letting you click on a specially crafted link. You would login, and get redirected to the site of the attacker, letting you think that you are still on the original Plone site. Or some javascript of the attacker could be executed. Most of these types of attacks are already blocked by Plone, using the `isURLInPortal` check to make sure we only redirect to a page on the same Plone site. But a few more ways of tricking Plone into accepting a malicious link were discovered, and fixed with this hotfix.",
"id": "GHSA-8g72-gq68-6gqh",
"modified": "2024-10-17T20:58:40Z",
"published": "2022-05-14T03:49:10Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2017-1000481"
},
{
"type": "WEB",
"url": "https://github.com/plone/Products.CMFPlone/issues/2232"
},
{
"type": "WEB",
"url": "https://github.com/plone/Products.CMFPlone/pull/2233"
},
{
"type": "WEB",
"url": "https://github.com/plone/Products.CMFPlone/pull/2234"
},
{
"type": "WEB",
"url": "https://github.com/plone/Products.CMFPlone/pull/2235"
},
{
"type": "WEB",
"url": "https://github.com/plone/Products.CMFPlone/pull/2236"
},
{
"type": "WEB",
"url": "https://github.com/plone/Products.CMFPlone/commit/05a943ecbcdda56bacc93b55c9e2e908d8a7dfab"
},
{
"type": "WEB",
"url": "https://github.com/plone/Products.CMFPlone/commit/0e50e1e67ea3b6d3187f78cb1a1628081f654d3b"
},
{
"type": "WEB",
"url": "https://github.com/plone/Products.CMFPlone/commit/236b62b756ff46a92783b3897e717dfb15eb07d8"
},
{
"type": "WEB",
"url": "https://github.com/plone/Products.CMFPlone/commit/7db5b2c8fb684055987b8c4fdedc29289bd26373"
},
{
"type": "PACKAGE",
"url": "https://github.com/plone/Products.CMFPlone"
},
{
"type": "WEB",
"url": "https://github.com/pypa/advisory-database/tree/main/vulns/plone/PYSEC-2018-70.yaml"
},
{
"type": "WEB",
"url": "https://plone.org/security/hotfix/20171128/open-redirection-on-login-form"
}
],
"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"
},
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N",
"type": "CVSS_V4"
}
],
"summary": "Products.CMFPlone Open Redirect Vulnerability"
}
GHSA-8G8P-FJX7-326C
Vulnerability from github – Published: 2022-05-14 01:49 – Updated: 2022-05-14 01:49Due to insufficient URL Validation in forums in SAP NetWeaver versions 7.30, 7.31, 7.40, an attacker can redirect users to a malicious site.
{
"affected": [],
"aliases": [
"CVE-2018-2476"
],
"database_specific": {
"cwe_ids": [
"CWE-601"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2018-11-13T20:29:00Z",
"severity": "MODERATE"
},
"details": "Due to insufficient URL Validation in forums in SAP NetWeaver versions 7.30, 7.31, 7.40, an attacker can redirect users to a malicious site.",
"id": "GHSA-8g8p-fjx7-326c",
"modified": "2022-05-14T01:49:23Z",
"published": "2022-05-14T01:49:23Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2018-2476"
},
{
"type": "WEB",
"url": "https://launchpad.support.sap.com/#/notes/2658755"
},
{
"type": "WEB",
"url": "https://wiki.scn.sap.com/wiki/pages/viewpage.action?pageId=503809832"
},
{
"type": "WEB",
"url": "http://www.securityfocus.com/bid/105898"
}
],
"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-8G9M-VV69-7J99
Vulnerability from github – Published: 2022-10-10 19:00 – Updated: 2024-11-22 20:17A lack of user input validation leads to an open redirect vulnerability in rdiffweb prior to 2.5.0a4.
{
"affected": [
{
"package": {
"ecosystem": "PyPI",
"name": "rdiffweb"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "2.5.0a4"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2022-3438"
],
"database_specific": {
"cwe_ids": [
"CWE-601"
],
"github_reviewed": true,
"github_reviewed_at": "2022-10-10T21:35:54Z",
"nvd_published_at": "2022-10-10T12:15:00Z",
"severity": "MODERATE"
},
"details": "A lack of user input validation leads to an open redirect vulnerability in rdiffweb prior to 2.5.0a4.",
"id": "GHSA-8g9m-vv69-7j99",
"modified": "2024-11-22T20:17:47Z",
"published": "2022-10-10T19:00:18Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2022-3438"
},
{
"type": "WEB",
"url": "https://github.com/ikus060/rdiffweb/commit/4d464b467f14b8eb9103d7f5f0774e49995527c7"
},
{
"type": "PACKAGE",
"url": "https://github.com/ikus060/rdiffweb"
},
{
"type": "WEB",
"url": "https://github.com/pypa/advisory-database/tree/main/vulns/rdiffweb/PYSEC-2022-43158.yaml"
},
{
"type": "WEB",
"url": "https://huntr.dev/bounties/bc5689e4-221a-4200-a8ab-42c659f89f67"
}
],
"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": "rdiffweb vulnerable to Open Redirect"
}
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.