CVE-2017-0885 : What You Need to Know

Nextcloud Server versions prior to 9.0.55 and 10.0.2 are affected by a vulnerability that exposes file information through error messages.

Understanding CVE-2017-0885

An issue in Nextcloud Server versions before 9.0.55 and 10.0.2 allows malicious actors to determine file and subfolder names in a write-only shared location.

What is CVE-2017-0885?

The vulnerability in Nextcloud Server versions prior to 9.0.55 and 10.0.2 exposes file and subfolder names through error messages, potentially aiding attackers in reconnaissance activities.

The Impact of CVE-2017-0885

This vulnerability enables unauthorized users with access to a write-only share to extract sensitive information, compromising the confidentiality of stored data.

Technical Details of CVE-2017-0885

Nextcloud Server versions before 9.0.55 and 10.0.2 are susceptible to information exposure through error messages.

Vulnerability Description

Due to an error in application logic, adversaries can enumerate existing file and subfolder names by analyzing exception messages in write-only shares.

Affected Systems and Versions

Product: Nextcloud Server
Vendor: Nextcloud
Versions Affected: All versions before 9.0.55 and 10.0.2

Exploitation Mechanism

The vulnerability allows attackers with write-only share access to deduce file and subfolder names by studying error messages, potentially aiding in unauthorized data access.

Mitigation and Prevention

Immediate Steps to Take:

Upgrade Nextcloud Server to version 9.0.55 or 10.0.2 to mitigate the vulnerability.
Restrict access to write-only shares to authorized users only.

Long-Term Security Practices

Regularly monitor and review error messages and logs for unusual activities.
Implement access controls and permissions to limit exposure of sensitive information.

Patching and Updates

Apply security patches and updates provided by Nextcloud to address the vulnerability and enhance system security.