A vulnerability, which was classified as critical, has been found in GetSimple CMS up to 3.3.15 (Content Management System). Affected by this issue is an unknown part of the file theme-edit.php. The manipulation with an unknown input leads to a credentials management vulnerability. Using CWE to declare the problem leads to CWE-255. Impacted is confidentiality, integrity, and availability. CVE summarizes:

An issue was discovered in GetSimple CMS through 3.3.15. insufficient input sanitation in the theme-edit.php file allows upload of files with arbitrary content (PHP code, for example). This vulnerability is triggered by an authenticated user; however, authentication can be bypassed. According to the official documentation for installation step 10, an admin is required to upload all the files, including the .htaccess files, and run a health check. However, what is overlooked is that the Apache HTTP Server by default no longer enables the AllowOverride directive, leading to data/users/admin.xml password exposure. The passwords are hashed but this can be bypassed by starting with the data/other/authorization.xml API key. This allows one to target the session state, since they decided to roll their own implementation. The cookie_name is crafted information that can be leaked from the frontend (site name and version). If a someone leaks the API key and the admin username, then they can bypass authentication. To do so, they need to supply a cookie based on an SHA-1 computation of this known information. The vulnerability exists in the admin/theme-edit.php file. This file checks for forms submissions via POST requests, and for the csrf nonce. If the nonce sent is correct, then the file provided by the user is uploaded. There is a path traversal allowing write access outside the jailed themes directory root. Exploiting the traversal is not necessary because the .htaccess file is ignored. A contributing factor is that there isn't another check on the extension before saving the file, with the assumption that the parameter content is safe. This allows the creation of web accessible and executable files with arbitrary content.

The bug was discovered 05/16/2019. The weakness was disclosed 05/22/2019. This vulnerability is handled as CVE-2019-11231 since 04/14/2019. The attack may be launched remotely. A simple authentication is necessary for exploitation. Technical details are known, but there is no available exploit. This vulnerability is assigned to T1552 by the MITRE ATT&CK project.

The vulnerability was handled as a non-public zero-day exploit for at least 6 days. During that time the estimated underground price was around $0-$5k. By approaching the search of inurl:theme-edit.php it is possible to find vulnerable targets with Google Hacking.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

Productinfo

Type

• Content Management System

Vendor

• GetSimple

Name

• CMS

Version

• 3.3.0
• 3.3.1
• 3.3.2
• 3.3.3
• 3.3.4
• 3.3.5
• 3.3.6
• 3.3.7
• 3.3.8
• 3.3.9
• 3.3.10
• 3.3.11
• 3.3.12
• 3.3.13
• 3.3.14
• 3.3.15

License

• free

CPE 2.3info

• 🔍
• 🔍
• 🔍

CPE 2.2info

• 🔍
• 🔍
• 🔍

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