CVE-2017-6026 Explained : Impact and Mitigation

Schneider Electric Modicon PLCs, specifically Modicon M241 and Modicon M251, have a vulnerability related to insufficiently random values, potentially compromising ongoing sessions.

Understanding CVE-2017-6026

Schneider Electric Modicon PLCs are affected by a Use of Insufficiently Random Values issue, allowing session compromise due to inadequate randomization of session numbers.

What is CVE-2017-6026?

The vulnerability in Schneider Electric Modicon PLCs arises from the generation of session numbers lacking proper randomization, leading to shared numbers among users and a risk of session compromise.

The Impact of CVE-2017-6026

The vulnerability poses a significant risk as attackers could potentially compromise ongoing sessions, leading to unauthorized access and control over affected systems.

Technical Details of CVE-2017-6026

Schneider Electric Modicon PLCs are susceptible to exploitation due to the following technical details:

Vulnerability Description

The issue lies in the web application's generation of session numbers, which are not sufficiently randomized, allowing multiple users to share the same numbers and potentially leading to session compromise.

Affected Systems and Versions

Schneider Electric Modicon PLCs, specifically Modicon M241 (firmware versions before Version 4.0.5.11) and Modicon M251 (firmware versions before Version 4.0.5.11)

Exploitation Mechanism

Attackers can exploit this vulnerability by intercepting and using shared session numbers to compromise ongoing sessions on affected Schneider Electric Modicon PLCs.

Mitigation and Prevention

To address CVE-2017-6026 and enhance security measures, consider the following steps:

Immediate Steps to Take

Update affected Schneider Electric Modicon PLCs to firmware Version 4.0.5.11 or later to mitigate the vulnerability.
Monitor and restrict access to the web application to prevent unauthorized users from exploiting the issue.

Long-Term Security Practices

Implement strong session management practices to ensure proper randomization of session numbers.
Regularly review and update security protocols to address potential vulnerabilities and enhance overall system security.

Patching and Updates

Stay informed about security advisories and updates from Schneider Electric to promptly apply patches and fixes to mitigate known vulnerabilities.