CVE-2020-27632 : Vulnerability Insights and Analysis

SIMATIC MV400 family versions prior to v7.0.6 have a vulnerability where the ISN generator is predictable, allowing for potential TCP session hijacking.

Understanding CVE-2020-27632

This CVE identifies a security issue in SIMATIC MV400 family versions before v7.0.6, impacting the ISN generator's predictability.

What is CVE-2020-27632?

The vulnerability in SIMATIC MV400 family versions prior to v7.0.6 allows attackers to predict and hijack TCP sessions due to the ISN generator's constant initialization and increments.

The Impact of CVE-2020-27632

Attackers can exploit this vulnerability to predict and potentially hijack TCP sessions, compromising network security.

Technical Details of CVE-2020-27632

SIMATIC MV400 family versions prior to v7.0.6 are affected by a predictable ISN generator, leading to potential security risks.

Vulnerability Description

The ISN generator in affected versions is initialized with a constant value and has constant increments, making TCP sessions predictable and vulnerable to hijacking.

Affected Systems and Versions

Vendor: n/a
Product: n/a
Versions: All versions prior to v7.0.6

Exploitation Mechanism

Attackers can exploit the predictable ISN generator to anticipate TCP session values, enabling them to hijack connections and potentially launch further attacks.

Mitigation and Prevention

Steps to address and prevent the CVE-2020-27632 vulnerability.

Immediate Steps to Take

Update SIMATIC MV400 family devices to version v7.0.6 or newer to mitigate the ISN generator predictability.
Monitor network traffic for any unusual activity that may indicate TCP session hijacking attempts.

Long-Term Security Practices

Implement network segmentation to limit the impact of potential TCP session hijacking.
Regularly review and update security policies and configurations to enhance overall network security.

Patching and Updates

Apply patches and updates provided by the vendor to address the ISN generator predictability issue and enhance network security.