CVE-2020-36249 : Exploit Details and Defense Strategies

The File Firewall before 2.8.0 for ownCloud Server has a vulnerability that allows bypassing file-type restrictions for public shares.

Understanding CVE-2020-36249

This CVE involves a security issue in the File Firewall of ownCloud Server that could lead to unauthorized access to files shared publicly.

What is CVE-2020-36249?

The vulnerability in the File Firewall before version 2.8.0 of ownCloud Server enables users to bypass file-type restrictions when sharing files publicly, potentially exposing sensitive information.

The Impact of CVE-2020-36249

The impact of this CVE is rated as high, with a network-based attack complexity. While it does not directly impact availability, confidentiality, or integrity, it can result in unauthorized access to shared files.

Technical Details of CVE-2020-36249

This section provides more technical insights into the vulnerability.

Vulnerability Description

The File Firewall before version 2.8.0 of ownCloud Server fails to enforce file-type restrictions for public shares, allowing users to share any file type regardless of the intended restrictions.

Affected Systems and Versions

Product: ownCloud Server
Vendor: ownCloud
Versions affected: All versions before 2.8.0

Exploitation Mechanism

The vulnerability can be exploited by users with access to the File Firewall feature, enabling them to upload and share files of any type publicly.

Mitigation and Prevention

To address CVE-2020-36249, follow these mitigation steps:

Immediate Steps to Take

Update ownCloud Server to version 2.8.0 or later to patch the vulnerability.
Review and adjust file-sharing permissions to restrict public sharing.

Long-Term Security Practices

Regularly monitor and audit file-sharing activities to detect unauthorized access.
Educate users on secure file-sharing practices to prevent inadvertent data exposure.

Patching and Updates

Apply security patches promptly to ensure the latest fixes are in place.