CVE-2019-0040 : What You Need to Know

In April 2019, Juniper Networks identified a vulnerability in Junos OS that could potentially lead to information exposure and partial Denial of Service (DoS) attacks.

Understanding CVE-2019-0040

This CVE involves a flaw in the rpcbind service in Junos OS, allowing specially crafted packets to trigger responses from the management interface, potentially revealing internal addressing and causing a partial DoS.

What is CVE-2019-0040?

The vulnerability in Junos OS allows responses to be generated from the management interface's source address, potentially exposing internal addressing and the presence of the management interface. Crafted packets targeting port 111 may lead to a partial DoS situation.

The Impact of CVE-2019-0040

The vulnerability could result in information exposure and partial Denial of Service (DoS) attacks, affecting systems running Junos OS based on FreeBSD 10 or higher.

Technical Details of CVE-2019-0040

Vulnerability Description

The rpcbind service in Junos OS may respond from the management interface, revealing internal addressing. Crafted packets to port 111 could cause a partial DoS.

Affected Systems and Versions

Junos OS versions 15.1 to 17.4 are affected, with specific releases mentioned in the data.

Exploitation Mechanism

The vulnerability allows responses from the management interface, potentially exposing internal addressing.

Mitigation and Prevention

Immediate Steps to Take

Use access lists or firewall filters to restrict access to port 111.
Disable the management interface (fxp0) if not essential.
Optionally, disable rpcbind via the configuration command.

Long-Term Security Practices

Regularly update Junos OS to the patched versions mentioned in the solution.

Patching and Updates

Juniper Networks has released updated software versions to address this vulnerability.