CVE-2017-5865 : What You Need to Know

This CVE involves a vulnerability in the password reset feature of ownCloud Server versions prior to 8.1.11, 8.2.x prior to 8.2.9, 9.0.x prior to 9.0.7, and 9.1.x prior to 9.1.3 that allows attackers to enumerate user names remotely.

Understanding CVE-2017-5865

What is CVE-2017-5865?

The vulnerability in the password reset functionality of ownCloud Server allows attackers to determine valid usernames by exploiting varying error messages.

The Impact of CVE-2017-5865

Attackers can remotely enumerate user names by launching multiple password reset attempts due to the vulnerability in ownCloud Server versions.

Technical Details of CVE-2017-5865

Vulnerability Description

The password reset feature in ownCloud Server versions prior to 8.1.11, 8.2.x prior to 8.2.9, 9.0.x prior to 9.0.7, and 9.1.x prior to 9.1.3 sends different error messages based on the validity of the username, enabling attackers to enumerate user names remotely.

Affected Systems and Versions

ownCloud Server versions prior to 8.1.11
ownCloud Server 8.2.x prior to 8.2.9
ownCloud Server 9.0.x prior to 9.0.7
ownCloud Server 9.1.x prior to 9.1.3

Exploitation Mechanism

Attackers exploit the vulnerability by sending numerous password reset attempts, leveraging the varying error messages to determine valid usernames.

Mitigation and Prevention

Immediate Steps to Take

Upgrade ownCloud Server to versions 8.1.11, 8.2.9, 9.0.7, or 9.1.3 to mitigate the vulnerability.
Monitor password reset attempts for unusual patterns or high volume.

Long-Term Security Practices

Implement multi-factor authentication to enhance user account security.
Regularly review and update security configurations to address emerging threats.

Patching and Updates

Apply security patches and updates provided by ownCloud to address the vulnerability effectively.