CVE-2022-39346 Explained : Impact and Mitigation

Nextcloud server, an open-source personal cloud server, had a vulnerability in which user display names were not properly limited. This issue could be exploited by malicious users to overload the database, leading to a denial of service attack. Upgrading to Nextcloud Server versions 22.2.10, 23.0.7, or 24.0.3 is recommended.

Understanding CVE-2022-39346

Nextcloud server versions prior to 22.2.10, 23.0.7, and 24.0.3 did not enforce proper restrictions on user display names, posing a risk of database overload and denial of service.

What is CVE-2022-39346?

The CVE-2022-39346 vulnerability in Nextcloud server allows malicious users to cause a denial of service attack by overloading the backing database.

The Impact of CVE-2022-39346

The lack of proper validation for user display names in affected versions of Nextcloud server could result in a database overload, leading to service disruption.

Technical Details of CVE-2022-39346

Vulnerability Description

Nextcloud server versions below 22.2.10, 23.0.7, and 24.0.3 did not have adequate controls on user display names, enabling potential database overload and denial of service.

Affected Systems and Versions

Vendor: Nextcloud
Product: Security Advisories
Affected Versions:
Version < 22.2.10
Version >= 23.0.0, < 23.0.7
Version >= 24.0.0, < 24.0.3

Exploitation Mechanism

Malicious users exploit the lack of length validation in user display names to cause a denial of service by overwhelming the database.

Mitigation and Prevention

Immediate Steps to Take

Upgrade the Nextcloud Server to versions 22.2.10, 23.0.7, or 24.0.3 to address the vulnerability and prevent potential denial of service attacks.

Long-Term Security Practices

Enforce strict input validation and implement proper length controls for user display names to mitigate similar vulnerabilities in the future.

Patching and Updates

Stay informed about security advisories and promptly apply patches released by Nextcloud to ensure the ongoing security of the server.