CVE-2019-15705 : What You Need to Know

FortiGate SSL VPN portal in FortiOS versions 6.2.1 and below, and 6.0.6 and below is vulnerable to a Denial of Service attack due to Improper Input Validation.

Understanding CVE-2019-15705

The vulnerability in FortiGate's SSL VPN portal allows unauthenticated remote attackers to crash the SSL VPN service.

What is CVE-2019-15705?

An Improper Input Validation vulnerability in FortiOS versions 6.2.1 and below, and 6.0.6 and below enables attackers to disrupt the SSL VPN service by sending a specially crafted POST request.

The Impact of CVE-2019-15705

Attackers can exploit this vulnerability remotely without authentication.
The SSL VPN service can be crashed, leading to a Denial of Service condition.

Technical Details of CVE-2019-15705

The following technical details provide insight into the vulnerability.

Vulnerability Description

The SSL VPN portal in FortiOS versions 6.2.1 and below, and 6.0.6 and below is susceptible to a Denial of Service attack due to improper input validation.

Affected Systems and Versions

Product: FortiGate
Vendor: Fortinet
Affected Versions: FortiOS versions 6.2.1 and below, FortiOS versions 6.0.6 and below

Exploitation Mechanism

Attackers can crash the SSL VPN service by sending a specially crafted POST request.

Mitigation and Prevention

Protect your systems from CVE-2019-15705 with the following measures.

Immediate Steps to Take

Apply patches provided by Fortinet promptly.
Monitor network traffic for any suspicious activity.
Restrict access to the SSL VPN portal.

Long-Term Security Practices

Regularly update and patch FortiOS to the latest version.
Implement network segmentation to limit the impact of potential attacks.
Conduct security assessments and penetration testing regularly.

Patching and Updates

Ensure timely installation of security patches and updates from Fortinet to mitigate the vulnerability.