CVE-2022-21681

Marked is a markdown parser and compiler. Prior to version 4.0.10, the regular expression `inline.reflinkSearch` may cause catastrophic backtracking against some strings and lead to a denial of service (DoS). Anyone who runs untrusted markdown through a vulnerable version of marked and does not use a worker with a time limit may be affected. This issue is patched in version 4.0.10. As a workaround, avoid running untrusted markdown through marked or run marked on a worker thread and set a reasonable time limit to prevent draining resources.

Marked is a markdown parser and compiler. Prior to version 4.0.10, the regular expression `inline.reflinkSearch` may cause catastrophic backtracking against some strings and lead to a denial of service (DoS). Anyone who runs untrusted markdown through a vulnerable version of marked and does not use a worker with a time limit may be affected. This issue is patched in version 4.0.10. As a workaround, avoid running untrusted markdown through marked or run marked on a worker thread and set a reasonable time limit to prevent draining resources.

### Impact _What kind of vulnerability is it?_ Denial of service. The regular expression `inline.reflinkSearch` may cause catastrophic backtracking against some strings. PoC is the following. ```javascript import * as marked from 'marked'; console.log(marked.parse(`[x]: x \\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](`)); ``` _Who is impacted?_ Anyone who runs untrusted markdown through marked and does not use a worker with a time limit. ### Patches _Has the problem been patched?_ Yes _What versions should users upgrade to?_ 4.0.10 ### Workarounds _Is there a way for users to fix or remediate the vulnerability without upgrading?_ Do not run untrusted markdown through marked or run marked on a [worker](https://marked.js.org/using_advanced#workers) thread and set a reasonable time limit to prevent draining resources. ### References _Are there any links users can visit to find out more?_ - https://marked.js.org/using_advanced#workers - https://owasp.org/www-community/attacks/Regular_expression_Denial_of_Service_-_ReDoS ### For more information If you have any questions or comments about this advisory: * Open an issue in [marked](https://github.com/markedjs/marked)

### Impact _What kind of vulnerability is it?_ Denial of service. The regular expression `inline.reflinkSearch` may cause catastrophic backtracking against some strings. PoC is the following. ```javascript import * as marked from 'marked'; console.log(marked.parse(`[x]: x \\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](\\[\\](`)); ``` _Who is impacted?_ Anyone who runs untrusted markdown through marked and does not use a worker with a time limit. ### Patches _Has the problem been patched?_ Yes _What versions should users upgrade to?_ 4.0.10 ### Workarounds _Is there a way for users to fix or remediate the vulnerability without upgrading?_ Do not run untrusted markdown through marked or run marked on a [worker](https://marked.js.org/using_advanced#workers) thread and set a reasonable time limit to prevent draining resources. ### References _Are there any links users can visit to find out more?_ - https://marked.js.org/using_advanced#workers - https://owasp.org/www-community/attacks/Regular_expression_Denial_of_Service_-_ReDoS ### For more information If you have any questions or comments about this advisory: * Open an issue in [marked](https://github.com/markedjs/marked)

Marked es un analizador y compilador de markdown. En versiones anteriores a 4.0.10, la expresión regular "inline.reflinkSearch" podía causar un retroceso catastrófico contra algunas cadenas y conllevar a una denegación de servicio (DoS). Cualquiera que ejecute markdown no confiable mediante una versión vulnerable de marked y no use un trabajador con límite de tiempo puede verse afectado. Este problema está parcheado en la versión 4.0.10. Como medida de mitigación, evite ejecutar markdown no confiable mediante marked o ejecute marked en un hilo de trabajo y establezca un límite de tiempo razonable para evitar el agotamiento de los recursos