CVE-2020-17516 Explained : Impact and Mitigation

Apache Cassandra versions 2.1.0 to 2.1.22, 2.2.0 to 2.2.19, 3.0.0 to 3.0.23, and 3.11.0 to 3.11.9 are affected by a vulnerability that allows both encrypted and unencrypted internode connections when using specific settings. This can lead to an authentication bypass by spoofing.

Understanding CVE-2020-17516

This CVE affects Apache Cassandra versions 2.1.0 to 2.1.22, 2.2.0 to 2.2.19, 3.0.0 to 3.0.23, and 3.11.0 to 3.11.9.

What is CVE-2020-17516?

Apache Cassandra versions mentioned above, when configured with 'dc' or 'rack' internode_encryption settings, allow both encrypted and unencrypted internode connections. This misconfiguration can enable a malicious user to bypass mutual TLS requirements.

The Impact of CVE-2020-17516

The vulnerability can be exploited by a misconfigured node or a malicious user to establish unencrypted connections despite not being in the same rack or data center, potentially leading to an authentication bypass by spoofing.

Technical Details of CVE-2020-17516

Apache Cassandra vulnerability details.

Vulnerability Description

The issue arises from the ability of misconfigured nodes or malicious users to utilize unencrypted connections despite the intended encryption settings, potentially bypassing mutual TLS requirements.

Affected Systems and Versions

Apache Cassandra 2.1.0 to 2.1.22
Apache Cassandra 2.2.0 to 2.2.19
Apache Cassandra 3.0.0 to 3.0.23
Apache Cassandra 3.11.0 to 3.11.9

Exploitation Mechanism

The vulnerability allows attackers to establish unencrypted connections, bypassing the expected mutual TLS requirement, by exploiting misconfigured nodes or malicious actions.

Mitigation and Prevention

Protect your systems from CVE-2020-17516.

Immediate Steps to Take

Update Apache Cassandra to the latest patched version.
Review and adjust internode_encryption settings to ensure secure configurations.
Monitor network traffic for any suspicious activities.

Long-Term Security Practices

Regularly review and update security configurations.
Conduct security audits to identify and address vulnerabilities.
Educate personnel on secure configuration practices.

Patching and Updates

Ensure timely application of security patches and updates to Apache Cassandra to mitigate the CVE-2020-17516 vulnerability.