CVE-2021-31158 : Security Advisory and Response

A vulnerability has been identified in the Query Engine of Couchbase Server versions 6.5.x and 6.6.x through 6.6.1. This CVE allows users to gain unauthorized read access beyond their intended permission levels.

Understanding CVE-2021-31158

This section provides an overview of the vulnerability.

What is CVE-2021-31158?

The CVE-2021-31158 vulnerability exists in the Query Engine of Couchbase Server versions 6.5.x and 6.6.x through 6.6.1. It allows users to access resources beyond their permitted scope due to inadequate permission checks.

The Impact of CVE-2021-31158

The impact of this vulnerability is that unauthorized users can potentially view and access data that they should not have the rights to, compromising data confidentiality.

Technical Details of CVE-2021-31158

This section delves into the technical aspects of the vulnerability.

Vulnerability Description

The vulnerability arises from Common Table Expression queries not properly validating user permissions, leading to unauthorized access to resources.

Affected Systems and Versions

Couchbase Server versions 6.5.x and 6.6.x through 6.6.1 are affected by this vulnerability.

Exploitation Mechanism

Attackers can exploit this vulnerability by crafting CTE queries to bypass permission restrictions and gain unauthorized access.

Mitigation and Prevention

Here are the steps to mitigate and prevent exploitation of CVE-2021-31158.

Immediate Steps to Take

Update Couchbase Server to the latest patched version that addresses the vulnerability.
Restrict user access to sensitive resources until the patch is applied.

Long-Term Security Practices

Regularly monitor and audit user permissions to prevent unauthorized access.
Educate users on best security practices to reduce the likelihood of exploitation.

Patching and Updates

Keep Couchbase Server up to date with the latest security patches and updates to protect against known vulnerabilities.