CVE-2021-23835 : What You Need to Know

A local file disclosure vulnerability has been discovered in flatCore before version 2.0.0 build 139, specifically in the

docs_file

HTTP request body parameter for the acp interface. This vulnerability allows exploitation with admin access rights, enabling the retrieval of sensitive backend server files such as /etc/passwd, SQLite database files, and PHP source code.

Understanding CVE-2021-23835

This section provides an overview of the vulnerability and its impact.

What is CVE-2021-23835?

The CVE-2021-23835 vulnerability is a local file disclosure issue in flatCore, a content management system, allowing attackers to access sensitive server files by exploiting the

docs_file

parameter.

The Impact of CVE-2021-23835

The impact of CVE-2021-23835 is significant as it enables threat actors to retrieve critical backend files like password databases and PHP source code, compromising the server's security.

Technical Details of CVE-2021-23835

Here, we delve into the technical aspects of the vulnerability.

Vulnerability Description

The vulnerability arises from the acceptance of unfiltered user input in the

docs_file

parameter, leading to unauthorized access to backend files.

Affected Systems and Versions

All versions of flatCore CMS before 2.0.0 build 139 are vulnerable to this file disclosure issue.

Exploitation Mechanism

Exploiting the

docs_file

parameter with admin access allows malicious actors to retrieve sensitive files, compromising the server's integrity.

Mitigation and Prevention

This section outlines steps to mitigate and prevent exploitation of CVE-2021-23835.

Immediate Steps to Take

Update flatCore CMS to version 2.0.0 build 139 or newer to patch the vulnerability.
Implement proper input validation and sanitization techniques to prevent unauthorized file access.

Long-Term Security Practices

Regularly update and monitor the CMS for security patches and vulnerabilities to ensure ongoing protection.

Patching and Updates

Frequently check for updates and patches from flatCore to address security issues and protect against file disclosure vulnerabilities.