CVE-2019-6811 Explained : Impact and Mitigation

The Modicon Quantum 140 NOE771x1 version 6.9 and earlier by Schneider Electric SE are vulnerable to a CWE-754 issue, leading to denial of service if the module receives oversized IP fragmented packets.

Understanding CVE-2019-6811

This CVE involves an Improper Check for Unusual or Exceptional Conditions vulnerability in the affected Schneider Electric SE product.

What is CVE-2019-6811?

The vulnerability in Modicon Quantum 140 NOE771x1 version 6.9 and earlier can result in denial of service due to the mishandling of large IP fragmented packets.

The Impact of CVE-2019-6811

The vulnerability can lead to a denial of service condition, requiring a power cycle to recover the affected module.

Technical Details of CVE-2019-6811

This section provides detailed technical information about the vulnerability.

Vulnerability Description

The vulnerability is classified as CWE-754, involving an Improper Check for Unusual or Exceptional Conditions.

Affected Systems and Versions

Product: Modicon Quantum 140 NOE771x1
Vendor: Schneider Electric SE
Versions Affected: version 6.9 and earlier

Exploitation Mechanism

The vulnerability is exploited by sending IP fragmented packets exceeding 65535 bytes to the module, triggering the denial of service.

Mitigation and Prevention

Protecting systems from CVE-2019-6811 requires immediate actions and long-term security practices.

Immediate Steps to Take

Monitor network traffic for unusually large IP fragmented packets
Implement network segmentation to isolate critical systems
Apply firewall rules to block oversized packets

Long-Term Security Practices

Regularly update firmware and software patches
Conduct security assessments and penetration testing
Educate staff on cybersecurity best practices

Patching and Updates

Check for patches or updates provided by Schneider Electric SE
Apply recommended patches promptly to mitigate the vulnerability