CVE-2024-21908: Tinymce Cross-Site Scripting Vulnerability
MODERATECVE-2024-21908 is a MODERATE (CVSS 6.1) cross-site scripting vulnerability (CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')) affecting Tinymce libraries in the npm ecosystem. The issue involves cross-site scripting vulnerability in tinymce. Remediation is available by upgrading affected packages to version 5.9.0.
CVE-2024-21908 at a Glance
Security Impact
CVSS: 6.1
The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N).
How to Fix CVE-2024-21908
To remediate this vulnerability, upgrade all affected Tinymce dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.
npm install tinymce@5.9.0Upgrade TinyMCE to 5.9.0Upgrade tinymce/tinymce to 5.9.0Run the following command in your project directory to verify that all resolved dependencies use the patched release:
npm ls tinymceHow to Check if You Are Affected
To determine whether your Node.js application is affected by CVE-2024-21908, inspect your project dependencies using npm:
npm ls tinymceAnalyze the terminal output to locate any version of Tinymce in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 5.9.0), your application is affected.
Note: The npm ls tinymce command inspects dependencies declared in your package.json and lockfile; it does not perform automated runtime dynamic scanning.
Technical Details
Vulnerability Mechanism & Technical Analysis
This vulnerability is classified under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting'), where the product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. In Tinymce, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.
Source Advisory Statement
CVE-2024-21908 Affected Tinymce Versions
3 component(s)| Product / Package | Ecosystem | Affected Versions | Fixed Version |
|---|---|---|---|
|
tinymce
|
npm |
< 5.9.0
|
5.9.0
|
|
TinyMCE
|
NuGet |
< 5.9.0
|
5.9.0
|
|
tinymce/tinymce
|
Packagist |
< 5.9.0
|
5.9.0
|
References
Frequently Asked Questions
What is CVE-2024-21908?
Which Tinymce versions are affected?
What version fixes CVE-2024-21908?
Is tinymce affected?
Is TinyMCE affected?
What is the CVSS score of CVE-2024-21908?
What CWE is associated with CVE-2024-21908?
How can I check npm dependencies for CVE-2024-21908?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-5h9g-x5rv-25wg",
"modified" : "2024-01-03T22:34:18Z",
"published" : "2021-10-22T16:24:02Z",
"aliases" : [ "CVE-2024-21908" ],
"summary" : "Cross-site scripting vulnerability in TinyMCE",
"details" : "### Impact\nA cross-site scripting (XSS) vulnerability was discovered in the schema validation logic of the core parser. The vulnerability allowed arbitrary JavaScript execution when inserting a specially crafted piece of content into the editor using the clipboard or editor APIs. This malicious content could then end up in content published outside the editor, if no server-side sanitization was performed. This impacts all users who are using TinyMCE 5.8.2 or lower.\n\n### Patches\nThis vulnerability has been patched in TinyMCE 5.9.0 by ensuring schema validation was still performed after unwrapping invalid elements.\n\n### Workarounds\nTo work around this vulnerability, either:\n- Upgrade to TinyMCE 5.9.0 or higher\n- Manually sanitize the content using the `BeforeSetContent` event (see below)\n\n#### Example: Manually sanitize content\n```js\neditor.on('BeforeSetContent', function(e) {\n var sanitizedContent = ...; // Manually sanitize content here\n e.content = sanitizedContent;\n});\n```\n\n### Acknowledgements\nTiny Technologies would like to thank William Bowling for discovering this vulnerability.\n\n### References\nhttps://www.tiny.cloud/docs/release-notes/release-notes59/#securityfixes\n\n### For more information\nIf you have any questions or comments about this advisory:\n* Email us at [infosec@tiny.cloud](mailto:infosec@tiny.cloud)\n* Open an issue in the [TinyMCE repo](https://github.com/tinymce/tinymce/issues)",
"severity" : [ {
"type" : "CVSS_V3",
"score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"
} ],
"affected" : [ {
"package" : {
"ecosystem" : "npm",
"name" : "tinymce"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "0"
}, {
"fixed" : "5.9.0"
} ]
} ]
}, {
"package" : {
"ecosystem" : "NuGet",
"name" : "TinyMCE"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "0"
}, {
"fixed" : "5.9.0"
} ]
} ]
}, {
"package" : {
"ecosystem" : "Packagist",
"name" : "tinymce/tinymce"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "0"
}, {
"fixed" : "5.9.0"
} ]
} ]
} ],
"references" : [ {
"type" : "WEB",
"url" : "https://github.com/tinymce/tinymce/security/advisories/GHSA-5h9g-x5rv-25wg"
}, {
"type" : "PACKAGE",
"url" : "https://github.com/tinymce/tinymce"
}, {
"type" : "WEB",
"url" : "https://www.tiny.cloud/docs/release-notes/release-notes59/#securityfixes"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-79" ],
"severity" : "MODERATE",
"github_reviewed" : true,
"github_reviewed_at" : "2021-10-22T13:49:23Z",
"nvd_published_at" : null
}
}