Zero-Day Advisory

Fortinet Discovers Schneider Electric Modicon Insecure Credential Transmission Vulnerability


Fortinet's FortiGuard Labs has discovered a cleartext transmission of sensitive information vulnerability in Schneider Electric Modicon products.

The Modicon PLC (Programmable Logic Controllers) control and monitor industrial operations in a sustainable, flexible, efficient and protected way.

The vulnerability exists because the login credentials are sent over the network in cleartext Base64 encoding. Attackers who can observe cleartext user credentials may be able to log in to the web application and perform unauthorized data monitoring or unauthorized operations.


FortiGuard Labs released the following FortiGate IPS signature which covers this specific vulnerability:

Released Sep 07, 2020

Users should apply the solution provided by Schneider Electric.


Fortinet reported the vulnerability to Schenider Electric on July 29, 2020.
Schneider Electric confirmed the vulnerability on August 4, 2020.
Schneider Electric patched the vulnerability on October 13, 2020.


This vulnerability was discovered by Kai Wang of Fortinet's FortiGuard Labs.

IPS Subscription

Fortinet customers who subscribe to Fortinet's intrusion prevention (IPS) service should be protected against this vulnerability with the appropriate configuration parameters in place. Fortinet's IPS service is one component of FortiGuard Subscription Services, which also offer comprehensive solutions such as antivirus, Web content filtering and antispam capabilities. These services enable protection against threats on both application and network layers. FortiGuard Services are continuously updated by FortiGuard Labs, which enables Fortinet to deliver a combination of multi-layered security intelligence and true zero-day protection from new and emerging threats. These updates are delivered to all FortiGate, FortiMail and FortiClient products. Fortinet strictly follows responsible disclosure guidelines to ensure optimum protection during a threat's lifecycle.