CVE-2021-34371 Explained : Impact and Mitigation

A vulnerability in Neo4j through version 3.4.18 with the shell server enabled allows an attacker to execute remote code by exploiting the RMI service that deserializes Java objects.

Understanding CVE-2021-34371

This CVE involves Neo4j database versions up to 3.4.18 with the shell server enabled, exposing an RMI service that maliciously deserializes Java objects, leading to potential remote code execution.

What is CVE-2021-34371?

Neo4j through version 3.4.18 is affected by a vulnerability where the RMI service can deserialize Java objects arbitrarily through functions like setSessionVariable. This flaw enables an attacker to achieve remote code execution due to exploitable gadget chains.

The Impact of CVE-2021-34371

The impact of this CVE is significant as attackers can exploit the deserialization of Java objects to execute malicious code remotely on affected systems. This could lead to unauthorized access, data theft, or further compromise of the Neo4j database.

Technical Details of CVE-2021-34371

This section explores the technical aspects of the CVE, including the vulnerability description, affected systems and versions, and the exploitation mechanism.

Vulnerability Description

The vulnerability stems from the RMI service in Neo4j versions up to 3.4.18 with the shell server enabled, allowing arbitrary deserialization of Java objects. The attacker can leverage this to execute remote code through specific gadget chains.

Affected Systems and Versions

Neo4j versions through 3.4.18 with the shell server enabled are impacted by this vulnerability. Users with these configurations are at risk of exploitation by malicious actors.

Exploitation Mechanism

By abusing the RMI service that deserializes Java objects, particularly through functions like setSessionVariable, threat actors can craft payloads to achieve remote code execution on vulnerable Neo4j installations.

Mitigation and Prevention

In response to CVE-2021-34371, organizations and users should implement immediate steps, adopt long-term security practices, and prioritize patching and updates.

Immediate Steps to Take

Ensure that the shell server is disabled in Neo4j versions up to 3.4.18 to mitigate the risk of remote code execution via the RMI service. Monitor for any unusual activities or attempted exploits.

Long-Term Security Practices

Establish strong access controls, regularly update Neo4j to the latest versions, conduct security assessments, and educate personnel on secure coding practices to enhance overall cybersecurity posture.

Patching and Updates

It is crucial to apply security patches provided by Neo4j promptly. Stay informed about security advisories and subscribe to relevant channels to receive notifications about new patches and updates.