CVE-2017-6028: Schneider Electric Modicon m241 Firmware

Critical severity, CVSS 9.8. EPSS: 2.3% chance of exploitation in the next 30 days.

An Insufficiently Protected Credentials issue was discovered in Schneider Electric Modicon PLCs Modicon M241, all firmware versions, and Modicon M251, all firmware versions. Log-in credentials are sent over the network with Base64 encoding leaving them susceptible to sniffing. Sniffed credentials could then be used to log into the web application.

Affected products

• Schneider Electric Modicon m241 Firmware: up to and including 4.0.3.20
• Schneider Electric Modicon m251 Firmware: up to and including 4.0.3.20

Published 2017-06-30. Last modified 2026-06-17.