CVE-2021-46668 : Security Advisory and Response

MariaDB through 10.5.9 allows an application crash via certain long SELECT DISTINCT statements that improperly interact with storage-engine resource limitations for temporary data structures.

Understanding CVE-2021-46668

MariaDB through version 10.5.9 is vulnerable to a crash caused by specific SELECT DISTINCT statements that do not handle storage-engine resource limits correctly.

What is CVE-2021-46668?

CVE-2021-46668 is a vulnerability in MariaDB versions up to 10.5.9 that can trigger an application crash when executing lengthy SELECT DISTINCT queries that encounter issues with temporary data structures' resource constraints.

The Impact of CVE-2021-46668

This vulnerability allows attackers to potentially crash applications that rely on MariaDB, disrupting services and causing denial of service.

Technical Details of CVE-2021-46668

MariaDB through 10.5.9 is susceptible to a specific type of SELECT DISTINCT query that exceeds storage-engine limits, leading to application crashes.

Vulnerability Description

The issue arises from handling large SELECT DISTINCT statements that surpass storage-engine limitations for temporary data structures.

Affected Systems and Versions

MariaDB versions up to 10.5.9 are impacted by this vulnerability.

Exploitation Mechanism

An attacker can exploit this vulnerability by crafting and executing lengthy SELECT DISTINCT queries that trigger the improper interaction with storage-engine limitations.

Mitigation and Prevention

To address CVE-2021-46668, consider the following steps:

Immediate Steps to Take

Upgrade MariaDB to a patched version that addresses the vulnerability.
Monitor database performance for any anomalies that might indicate exploitation.
Restrict network access to the database to trusted entities.
Implement strong access controls and authentication mechanisms.

Long-Term Security Practices

Regularly update and patch the database software to mitigate known vulnerabilities.
Conduct security assessments and penetration testing to identify and remediate potential weaknesses.
Follow secure coding practices to minimize the risk of introducing vulnerabilities.

Patching and Updates

Apply patches provided by MariaDB to fix the vulnerability and enhance system security.