Arbitrary file upload in Drupal



Published: 2020-11-18
Risk High
Patch available YES
Number of vulnerabilities 1
CVE ID CVE-2020-13671
CWE ID CWE-434
Exploitation vector Network
Public exploit N/A
Vulnerable software
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Drupal
Web applications / CMS

Vendor Drupal

Security Advisory

This security advisory describes one high risk vulnerability.

1) Arbitrary file upload

Risk: High

CVSSv3: 8.5 [CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C] [PCI]

CVE-ID: CVE-2020-13671

CWE-ID: CWE-434 - Unrestricted Upload of File with Dangerous Type

Exploit availability: No

Description

The vulnerability allows a remote attacker to compromise vulnerable system.

The vulnerability exists due to insufficient validation of file during file upload. A remote attacker can upload a malicious PHP file and execute it on the server.

Additionally, 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 .php.txt or .html.gif. Pay specific attention to the following file extensions, which should be considered dangerous even when followed by another extension:

  • phar
  • php
  • pl
  • py
  • cgi
  • asp
  • js
  • html
  • htm

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Drupal: 7.0, 7.1, 7.1-1.2, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9, 7.10, 7.11, 7.12, 7.13, 7.14, 7.15, 7.16, 7.17, 7.18, 7.19, 7.20, 7.21, 7.22, 7.23, 7.24, 7.25, 7.26, 7.27, 7.28, 7.29, 7.30, 7.31, 7.32, 7.33, 7.34, 7.35, 7.36, 7.37, 7.38, 7.39, 7.40, 7.41, 7.42, 7.43, 7.44, 7.50, 7.51, 7.52, 7.53, 7.54, 7.55, 7.56, 7.57, 7.58, 7.59, 7.60, 7.61, 7.62, 7.63, 7.64, 7.65, 7.66, 7.67, 7.68, 7.69, 7.70, 7.71, 7.72, 7.73, 7.x, 7.x-1.0, 7.x-1.1, 7.x-1.2, 7.x-1.3, 7.x-1.4, 7.x-dev, 8.0, 8.0.0, 8.0.0-beta6, 8.0.0-beta7, 8.0.0-beta8, 8.0.0-beta9, 8.0.0-beta10, 8.0.0-beta11, 8.0.0-beta12, 8.0.0-beta13, 8.0.0-beta14, 8.0.0-beta15, 8.0.0-beta16, 8.0.0-rc1, 8.0.0-rc2, 8.0.0-rc3, 8.0.0-rc4, 8.0.1, 8.0.2, 8.0.3, 8.0.4, 8.0.5, 8.0.6, 8.1.0, 8.1.0-beta1, 8.1.0-beta2, 8.1.0-rc1, 8.1.1, 8.1.2, 8.1.3, 8.1.4, 8.1.5, 8.1.6, 8.1.7, 8.1.8, 8.1.9, 8.1.10, 8.2.0, 8.2.0-beta1, 8.2.0-beta2, 8.2.0-beta3, 8.2.0-rc1, 8.2.0-rc2, 8.2.1, 8.2.2, 8.2.3, 8.2.4, 8.2.5, 8.2.6, 8.2.7, 8.2.8, 8.3.0, 8.3.0-alpha1, 8.3.0-beta1, 8.3.0-rc1, 8.3.0-rc2, 8.3.1, 8.3.2, 8.3.3, 8.3.4, 8.3.5, 8.3.6, 8.3.7, 8.3.8, 8.3.9, 8.4.0, 8.4.0-alpha1, 8.4.0-beta1, 8.4.0-rc1, 8.4.0-rc2, 8.4.1, 8.4.2, 8.4.3, 8.4.4, 8.4.5, 8.4.6, 8.4.7, 8.4.8, 8.5.0, 8.5.0-alpha1, 8.5.0-beta1, 8.5.0-rc1, 8.5.1, 8.5.2, 8.5.3, 8.5.4, 8.5.5, 8.5.6, 8.5.7, 8.5.8, 8.5.9, 8.5.10, 8.5.11, 8.5.12, 8.5.13, 8.5.14, 8.5.15, 8.6.0, 8.6.0-alpha1, 8.6.0-beta1, 8.6.0-beta2, 8.6.0-rc1, 8.6.1, 8.6.2, 8.6.3, 8.6.4, 8.6.5, 8.6.6, 8.6.7, 8.6.8, 8.6.9, 8.6.10, 8.6.11, 8.6.12, 8.6.13, 8.6.14, 8.6.15, 8.6.16, 8.6.17, 8.6.18, 8.7.0, 8.7.0-alpha1, 8.7.0-alpha2, 8.7.0-beta1, 8.7.0-beta2, 8.7.0-rc1, 8.7.1, 8.7.2, 8.7.3, 8.7.4, 8.7.5, 8.7.6, 8.7.7, 8.7.8, 8.7.9, 8.7.10, 8.7.11, 8.7.12, 8.7.13, 8.7.14, 8.8.0, 8.8.0-alpha1, 8.8.0-beta1, 8.8.0-rc1, 8.8.1, 8.8.2, 8.8.3, 8.8.4, 8.8.5, 8.8.6, 8.8.7, 8.8.8, 8.8.9, 8.8.10, 8.9.0, 8.9.0-beta1, 8.9.0-beta2, 8.9.0-beta3, 8.9.0-rc1, 8.9.1, 8.9.2, 8.9.3, 8.9.4, 8.9.5, 8.9.6, 8.9.7, 8.9.8, 9.0.0, 9.0.0-alpha1, 9.0.0-alpha2, 9.0.0-beta1, 9.0.0-beta2, 9.0.0-beta3, 9.0.0-rc1, 9.0.1, 9.0.2, 9.0.3, 9.0.4, 9.0.5, 9.0.6, 9.0.7

CPE External links

https://www.drupal.org/sa-core-2020-012

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.