CVE-2017-16798 : Security Advisory and Response

CMS Made Simple version 2.2.3.1 is vulnerable to a file upload restriction bypass issue that can lead to cross-site scripting attacks.

Understanding CVE-2017-16798

This CVE identifies a security vulnerability in CMS Made Simple version 2.2.3.1 that allows attackers to upload malicious files with extensions that can bypass access restrictions.

What is CVE-2017-16798?

The vulnerability in the is_file_acceptable function of CMS Made Simple version 2.2.3.1 allows files with extensions like .phtml, .pht, .html, or .svg to be uploaded, enabling attackers to bypass security measures and potentially execute cross-site scripting attacks.

The Impact of CVE-2017-16798

This vulnerability can be exploited by malicious actors to circumvent file upload restrictions, potentially leading to unauthorized access, data manipulation, or the execution of harmful scripts on the target system.

Technical Details of CVE-2017-16798

CMS Made Simple version 2.2.3.1 is affected by a specific vulnerability related to file upload handling.

Vulnerability Description

The is_file_acceptable function in the modules/FileManager/action.upload.php file of CMS Made Simple version 2.2.3.1 only blocks files with "php" in their extensions, allowing attackers to upload files with other dangerous extensions.

Affected Systems and Versions

Affected Version: CMS Made Simple 2.2.3.1

Exploitation Mechanism

Attackers can exploit this vulnerability by uploading files with extensions like .phtml, .pht, .html, or .svg, evading the file upload restrictions and potentially launching cross-site scripting attacks.

Mitigation and Prevention

To address CVE-2017-16798 and enhance system security, follow these mitigation strategies:

Immediate Steps to Take

Update CMS Made Simple to a patched version that addresses this vulnerability.
Implement strict file upload validation to block potentially harmful file extensions.

Long-Term Security Practices

Regularly monitor and audit file upload functionalities for any suspicious activities.
Educate users on safe file handling practices to prevent uploading malicious files.

Patching and Updates

Apply security patches and updates provided by CMS Made Simple to fix the vulnerability and strengthen system security.