CVE-2020-13671: Drupal Remote Code Execution Vulnerability Alert
On November 18, 2020, Drupal issued a risk notice for Drupal code execution vulnerability, the vulnerability number is CVE-2020-13671. The security risk is Critical. An unauthorized remote attacker can cause arbitrary code execution by uploading a file with a specific file name.
Vulnerability Detail
Drupal core does not properly sanitize certain filenames on uploaded files, which can lead to files being interpreted as the incorrect extension and served as the wrong MIME type or executed as PHP for certain hosting configurations.
Affected version
- Drupal: 9.0
- Drupal: 8.9
- Drupal: 8.8.x
- Drupal: 7
Unaffected version
Solution
In this regard, we recommend that users upgrade Drupal to the latest version in time.
Temporary repair suggestions
it’s recommended that you audit all previously uploaded files to check for malicious extensions. Look specifically for files that include more than one extension, like
filename.php.txtorfilename.html.gif, without an underscore (_) in the extension. Pay specific attention to the following file extensions, which should be considered dangerous even when followed by one or more additional extensions:
- phar
- php
- pl
- py
- cgi
- asp
- js
- html
- htm
- phtml
This list is not exhaustive, so evaluate security concerns for other unmunged extensions on a case-by-case basis.
