CVE-2023-45818: Tinymce Cross-Site Scripting Vulnerability
MODERATECVE-2023-45818 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 tinymce mxss vulnerability in undo/redo, getcontent api, resetcontent api, and autosave plugin. Remediation is available by upgrading affected packages to version 6.7.1, 5.10.8.
CVE-2023-45818 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-2023-45818
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@6.7.1
Upgrade TinyMCE to 6.7.1
Upgrade tinymce/tinymce to 6.7.1
npm install tinymce@5.10.8
Upgrade TinyMCE to 5.10.8
Upgrade tinymce/tinymce to 5.10.8
Run the following command in your project directory to verify that all resolved dependencies use the patched release:
npm ls tinymce
How to Check if You Are Affected
To determine whether your Node.js application is affected by CVE-2023-45818, inspect your project dependencies using npm:
npm ls tinymce
Analyze 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 6.7.1), 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-2023-45818 Affected Tinymce Versions
6 component(s)| Product / Package | Ecosystem | Affected Versions | Fixed Version |
|---|---|---|---|
|
tinymce
|
npm |
≥ 6.0.0
< 6.7.1
|
6.7.1
|
|
TinyMCE
|
NuGet |
≥ 6.0.0
< 6.7.1
|
6.7.1
|
|
tinymce/tinymce
|
Packagist |
≥ 6.0.0
< 6.7.1
|
6.7.1
|
|
tinymce
|
npm |
< 5.10.8
|
5.10.8
|
|
TinyMCE
|
NuGet |
< 5.10.8
|
5.10.8
|
|
tinymce/tinymce
|
Packagist |
< 5.10.8
|
5.10.8
|
References
Frequently Asked Questions
What is CVE-2023-45818?
Which Tinymce versions are affected?
What version fixes CVE-2023-45818?
Is tinymce affected?
Is TinyMCE affected?
What is the CVSS score of CVE-2023-45818?
What CWE is associated with CVE-2023-45818?
How can I check npm dependencies for CVE-2023-45818?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-v65r-p3vv-jjfv",
"modified" : "2023-11-15T23:24:58Z",
"published" : "2023-10-19T16:36:29Z",
"aliases" : [ "CVE-2023-45818" ],
"summary" : "TinyMCE mXSS vulnerability in undo/redo, getContent API, resetContent API, and Autosave plugin",
"details" : "### Impact\nA [mutation cross-site scripting](https://researchgate.net/publication/266654651_mXSS_attacks_Attacking_well-secured_web-applications_by_using_innerHTML_mutations) (mXSS) vulnerability was discovered in TinyMCE’s core undo and redo functionality. When a carefully-crafted HTML snippet passes the XSS sanitisation layer, it is manipulated as a string by internal trimming functions before being stored in the undo stack. If the HTML snippet is restored from the undo stack, the combination of the string manipulation and reparative parsing by either the browser's native [DOMParser API](https://developer.mozilla.org/en-US/docs/Web/API/DOMParser) (TinyMCE 6) or the [SaxParser API](https://www.tiny.cloud/docs/api/tinymce.html/tinymce.html.saxparser/) (TinyMCE 5) mutates the HTML maliciously, allowing an XSS payload to be executed.\nThis vulnerability also impacts these related TinyMCE APIs and plugins:\n* [`tinymce.Editor.getContent({ format: 'raw' })`](https://tiny.cloud/docs/tinymce/6/apis/tinymce.editor/#getContent)\n* [`tinymce.Editor.resetContent()`](https://tiny.cloud/docs/tinymce/6/apis/tinymce.editor/#resetContent)\n* [Autosave Plugin](https://tiny.cloud/docs/tinymce/6/autosave/)\n\n### Patches\nThis vulnerability has been patched in TinyMCE 5.10.8 and TinyMCE 6.7.1 by ensuring HTML is trimmed using node-level manipulation instead of string manipulation.\n\n### Fix\nTo avoid this vulnerability:\n* Upgrade to TinyMCE 5.10.8 or higher for TinyMCE 5.x.\n* Upgrade to TinyMCE 6.7.1 or higher for TinyMCE 6.x.\n\n### Acknowledgements\nTiny Technologies would like to thank Masato Kinugawa of [Cure53](https://cure53.de/) for discovering this vulnerability.\n\n### References\n* [TinyMCE 5.10.8 Release Notes](https://tiny.cloud/docs/release-notes/release-notes5108/)\n* [TinyMCE 6.7.1 Release Notes](https://tiny.cloud/docs/tinymce/6/6.7.1-release-notes/)\n\n### For more information\nIf you have any questions or comments about this advisory:\n* Email us at <infosec@tiny.cloud>\n* Open an issue in the [TinyMCE repo](https://github.com/tinymce/tinymce/issues?q=is%3Aissue+is%3Aopen+sort%3Aupdated-desc)",
"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" : "6.0.0"
}, {
"fixed" : "6.7.1"
} ]
} ]
}, {
"package" : {
"ecosystem" : "NuGet",
"name" : "TinyMCE"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "6.0.0"
}, {
"fixed" : "6.7.1"
} ]
} ]
}, {
"package" : {
"ecosystem" : "Packagist",
"name" : "tinymce/tinymce"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "6.0.0"
}, {
"fixed" : "6.7.1"
} ]
} ]
}, {
"package" : {
"ecosystem" : "npm",
"name" : "tinymce"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "0"
}, {
"fixed" : "5.10.8"
} ]
} ]
}, {
"package" : {
"ecosystem" : "NuGet",
"name" : "TinyMCE"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "0"
}, {
"fixed" : "5.10.8"
} ]
} ]
}, {
"package" : {
"ecosystem" : "Packagist",
"name" : "tinymce/tinymce"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "0"
}, {
"fixed" : "5.10.8"
} ]
} ]
} ],
"references" : [ {
"type" : "WEB",
"url" : "https://github.com/tinymce/tinymce/security/advisories/GHSA-v65r-p3vv-jjfv"
}, {
"type" : "ADVISORY",
"url" : "https://nvd.nist.gov/vuln/detail/CVE-2023-45818"
}, {
"type" : "PACKAGE",
"url" : "https://github.com/tinymce/tinymce"
}, {
"type" : "WEB",
"url" : "https://researchgate.net/publication/266654651_mXSS_attacks_Attacking_well-secured_web-applications_by_using_innerHTML_mutations"
}, {
"type" : "WEB",
"url" : "https://tiny.cloud/docs/release-notes/release-notes5108/#securityfixes"
}, {
"type" : "WEB",
"url" : "https://tiny.cloud/docs/tinymce/6/6.7.1-release-notes/#security-fixes"
}, {
"type" : "WEB",
"url" : "https://www.tiny.cloud/docs/api/tinymce.html/tinymce.html.saxparser"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-79" ],
"severity" : "MODERATE",
"github_reviewed" : true,
"github_reviewed_at" : "2023-10-19T16:36:29Z",
"nvd_published_at" : "2023-10-19T22:15:10Z"
}
}