Drupal H5P Module <= 2.0.0 (isValidPackage) Zip Slip Vulnerability
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[-] Software Link:
https://www.drupal.org/project/h5p
[-] Affected Versions:
Version 2.0.0-alpha2 and prior versions.
Version 7.x-1.50 and prior versions.
[-] Vulnerability Description:
The vulnerability is located within the H5PValidator::isValidPackage()
method. This implements the following check in order to skip any file or
folder starting with a dot or underscore within the uploaded h5p
archive:
891. $fileName = $zip->statIndex($i)[‘name’];
892.
893. if (preg_match(‘/(^[._]|/[._])/’, $fileName) !== 0) {
894. continue; // Skip any file or folder starting with a . or _
894. }
This regex check should be enough to prevent path traversal attacks
through zipped filenames (Zip Slip attacks), because it checks for the
string “/.” within the filename, thus preventing directory traversal
attacks. However, the vulnerability exists if Drupal is running on a
Windows server, because in this case the attacker can provide a
malicious h5p archive containing a filename with path traversal
sequences like “……”, which would bypass the above regex check.
This can be exploited to write (or overwrite) semi-arbitrary files in
the file system via directory traversal sequences, potentially leading
to Stored Cross-Site Scripting (XSS) and other kind of attacks.
[-] Solution:
No official solution is currently available.
[-] Disclosure Timeline:
[22/11/2021] – Vendor notified
[28/02/2022] – Vendor proposed a possible patch
[28/02/2022] – Vendor notified about the ineffective patch, provided a
fix suggestion
[01/03/2022] – Vendor fixed the previous patch
[30/03/2022] – Asked update about the public disclosure and release of a
patch, no response
[22/11/2022] – After one year still no official solution available
[03/12/2022] – Public disclosure
[-] CVE Reference:
The Common Vulnerabilities and Exposures project (cve.mitre.org)
has not assigned a CVE identifier for this vulnerability.
[-] Credits:
Vulnerability discovered by Egidio Romano.
[-] Other References:
https://security.drupal.org/node/175968
[-] Original Advisory:
http://karmainsecurity.com/KIS-2022-06
