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XenForo <= 2.2.13 (ArchiveImport.php) Zip Slip Vulnerability
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[-] Software Link:

https://xenforo.com


[-] Affected Versions:

Version 2.2.13 and prior versions.


[-] Vulnerability Description:

The vulnerability is located in the
/src/XF/Service/Style/ArchiveImport.php script. Specifically, into the
"ArchiveImport::extractFilesToTempDir()" method:

198. public function extractFilesToTempDir()
199. {
200. $zip = $this->zip();
201. $DS = \XF::$DS;
202.
203. if ($this->extracted)
204. {
205. return;
206. }
207.
208. for ($i = 0; $i < $zip->numFiles; $i++)
209. {
210. $zipFileName = $zip->getNameIndex($i);
211. $fsFileName = $this->getFsFileNameFromZipName($zipFileName);
212. if ($fsFileName === null)
213. {
214. continue;
215. }
216.
217. $finalFileName = $this->tempDir . $DS . $fsFileName;
218.
219. $dataStream = $zip->getStream($zipFileName);
220. @File::writeFile($finalFileName, $dataStream, false);
221. }

The vulnerability exists because the above code is using the filename
provided within the Zip archive ($zipFileName variable created at line
210) to write the extracted file by using "File::writeFile()" at line
220, without properly verifying whether it contains Path Traversal
sequences. This could be exploited to carry out Zip Slip (or Path
Traversal) attacks and write/overwrite arbitrary files on the web
server, resulting in execution of arbitrary PHP code or other security
impacts. Successful exploitation of this vulnerability requires an
account with permissions to administer styles.


[-] Solution:

Upgrade to version 2.2.14 or later.


[-] Disclosure Timeline:

[02-01-2024] - Vendor notified
[17-01-2024] - CVE identifier requested
[24-01-2024] - Vendor replied a fix will be available in the next release
[30-01-2024] - Version 2.2.14 released
[30-01-2024] - Publication of this advisory


[-] 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://xenforo.com/tickets/BC37EB98/?v=5da7bd5728


[-] Original Advisory:

http://karmainsecurity.com/KIS-2024-01