CVE-2022-31118 : Security Advisory and Response

Nextcloud Server is an open-source personal cloud solution that has been impacted by a vulnerability allowing attackers to potentially brute force access tokens for federated sharing. Upgrading to specific versions is recommended to mitigate this issue.

Understanding CVE-2022-31118

This CVE highlights a vulnerability in Nextcloud Server related to cloud federation sharing, potentially leading to unauthorized access attempts through brute force attacks.

What is CVE-2022-31118?

In affected versions of Nextcloud Server, attackers could exploit a lack of brute force protection to determine if federated sharing is being used. They could then attempt to brute force access tokens for federated shares with specified character patterns.

The Impact of CVE-2022-31118

The vulnerability, with a CVSS base score of 6.5, poses a medium severity risk. It could allow attackers to guess access tokens for federated shares, compromising the confidentiality of the information.

Technical Details of CVE-2022-31118

This section provides specific technical details related to the vulnerability.

Vulnerability Description

The vulnerability in Nextcloud Server enables attackers to brute force access tokens for federated shares with specific character patterns, potentially leading to unauthorized access.

Affected Systems and Versions

The affected versions include Nextcloud Server versions less than 22.2.9, between 23.0.0 to 23.0.6, and between 24.0.0 to 24.0.2.

Exploitation Mechanism

Attackers can exploit this vulnerability by attempting to guess the access tokens for federated shares through brute force attacks.

Mitigation and Prevention

It is crucial to take immediate steps to secure systems and prevent unauthorized access.

Immediate Steps to Take

Users are strongly advised to upgrade Nextcloud Server to versions 22.2.9, 23.0.6, or 24.0.2 to address this vulnerability. Alternatively, disabling federated sharing via the Admin Sharing settings can help mitigate the risk.

Long-Term Security Practices

In the long term, organizations should follow security best practices, regularly update their systems, and monitor for any unusual activities.

Patching and Updates

Regularly monitoring for security advisories and applying patches and updates promptly is essential in maintaining a secure Nextcloud Server environment.