Zero-Day Advisory

Fortinet Discovers Schneider Electric Modicon Embedded HTTP Server Stack Buffer Overflow Vulnerability

Summary

Fortinet's FortiGuard Labs has discovered a stack-based buffer overflow 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.


A stack-based buffer overflow (Buffer Copy without Checking Size of Input) vulnerability exists which could cause write access and the execution of commands by uploading a specially crafted file on the controller over FTP.

Solutions

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

Schneider.Electric.Modicon.Web.Server.Memory.Corruption
Released Nov 04, 2020

Users should apply the solution/workaround provided by Schneider Electric.

Timeline

Fortinet reported the vulnerability to Schneider Electric on Aug 11, 2020.

Schneider Electric confirmed the vulnerability on Oct 13, 2020.

Schneider Electric provided remediation on Nov 12, 2020.

Acknowledgement

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.