CVE-2025-3756: AC800M (System 800xA) 6.0.0x through 6.0.0303.0, 6.1.0x through 6.1.0031.0, 6.1.1x through 6.1.1004.0, 6.1.1x through…

Affected technology

AC800M (System 800xA) · 6.0.0x through 6.0.0303.0, 6.1.0x through 6.1.0031.0, 6.1.1x through 6.1.1004.0, 6.1.1x through 6.1.1202.0, 6.2.0x through 6.2.0006.0
ABB

Symphony Plus SD Series · A_0, A_1, A_2.003, A_3.005, A_4.001, B_0.005
ABB

Symphony Plus MR (Melody Rack) · 3.10 through 3.52
ABB

S+ Operations · 2.1, 2.2, 2.3, 3.3
ABB

Component: CI868, CI850, PM 877

Attack conditions (Vendor/CNA, CVSS 4.0): Adjacent network · No privileges required · No user interaction required

What an attacker can do

An attacker with access to IEC 61850 networks could exploit the vulnera bility by using a specially crafted 61850 packet, forcing the communication interfaces of the PM 877, CI850 and CI868 modules into fault mode or causing unavailability of the S+ Operations 61850 connectivity, resulting in a denial-of-service situation. Vendor/CNA’s CVSS 4.0 assessment (base score 7.1/10) rates confidentiality and integrity impact as none; availability impact as high.