CVE-2019-5598 : Security Advisory and Response

A vulnerability in FreeBSD versions before 11.2-RELEASE-p10 and 12.0-RELEASE-p4 could allow a maliciously crafted ICMP/ICMP6 packet to bypass packet filter rules.

Understanding CVE-2019-5598

This CVE involves a flaw in the pf software of FreeBSD that could be exploited by a specially crafted ICMP/ICMP6 packet.

What is CVE-2019-5598?

Prior to specific versions in FreeBSD, a flaw in the pf software allowed crafted ICMP/ICMP6 packets to evade packet filter rules.

The Impact of CVE-2019-5598

The vulnerability could enable an attacker to direct malicious packets to hosts that should be inaccessible, potentially leading to unauthorized access or denial of service.

Technical Details of CVE-2019-5598

This section provides more in-depth technical information about the vulnerability.

Vulnerability Description

The flaw in FreeBSD versions allowed ICMP/ICMP6 packets to bypass packet filter rules, potentially reaching hosts that should be unreachable.

Affected Systems and Versions

FreeBSD 11.2 before 11.2-RELEASE-p10
FreeBSD 12.0 before 12.0-RELEASE-p4

Exploitation Mechanism

By sending a specially crafted ICMP/ICMP6 packet, an attacker could exploit the flaw to direct packets to hosts that would normally be protected.

Mitigation and Prevention

Protecting systems from CVE-2019-5598 involves taking immediate and long-term security measures.

Immediate Steps to Take

Apply the necessary patches provided by FreeBSD promptly.
Monitor network traffic for any signs of exploitation.
Implement strict firewall rules to mitigate the risk of unauthorized access.

Long-Term Security Practices

Regularly update and patch FreeBSD systems to address known vulnerabilities.
Conduct security audits to identify and address potential weaknesses in the network infrastructure.

Patching and Updates

Ensure that FreeBSD systems are updated to versions 11.2-RELEASE-p10 and 12.0-RELEASE-p4 or later to mitigate the vulnerability effectively.