CVE-2019-12086 Explained : Impact and Mitigation

A vulnerability related to Polymorphic Typing has been identified in FasterXML jackson-databind 2.x, prior to version 2.9.9. This CVE allows an attacker to read arbitrary local files on the server by sending a manipulated JSON message.

Understanding CVE-2019-12086

This CVE affects FasterXML jackson-databind 2.x versions before 2.9.9 and involves a Polymorphic Typing issue that can be exploited to read arbitrary local files on the server.

What is CVE-2019-12086?

This vulnerability arises when Default Typing is enabled for a JSON endpoint with the mysql-connector-java jar in the classpath, allowing an attacker to host a manipulated MySQL server to exploit the issue.

The Impact of CVE-2019-12086

The lack of validation in the com.mysql.cj.jdbc.admin.MiniAdmin component enables attackers to read arbitrary local files on the server, posing a significant security risk.

Technical Details of CVE-2019-12086

This section provides detailed technical information about the vulnerability.

Vulnerability Description

The vulnerability in FasterXML jackson-databind 2.x versions before 2.9.9 allows attackers to read arbitrary local files on the server by sending a manipulated JSON message.

Affected Systems and Versions

FasterXML jackson-databind 2.x versions prior to 2.9.9
MySQL-connector-java jar versions 8.0.14 or earlier

Exploitation Mechanism

Attacker hosts a manipulated MySQL server accessible to the victim
Send a crafted JSON message to exploit the issue

Mitigation and Prevention

Protect your systems from CVE-2019-12086 with the following steps:

Immediate Steps to Take

Update FasterXML jackson-databind to version 2.9.9 or later
Ensure mysql-connector-java jar is updated to version 8.0.15 or newer
Disable Default Typing if not required

Long-Term Security Practices

Regularly monitor and update dependencies in your applications
Implement network segmentation to limit exposure of critical services
Conduct regular security assessments and penetration testing

Patching and Updates

Apply patches provided by FasterXML and MySQL to address the vulnerability
Stay informed about security updates and advisories from relevant vendors