Executive brief
MZ Automation libiec61850 is a software library used in the energy sector to implement communication protocols for electrical substation automation. A vulnerability in how the library handles specific data messages allows an attacker on the same local network to crash the service. This results in a denial-of-service condition, potentially disrupting the monitoring and control of critical power infrastructure.
Technical details
An out-of-bounds read vulnerability exists in the MMS BER decoder component of libiec61850. The flaw is located in the decoding logic for fixed-width Basic Encoding Rules (BER) fields, specifically booleans and integers. The decoder fails to validate attacker-supplied length values, leading to a read past the end of a heap buffer. An unauthenticated attacker on the adjacent network can exploit this by sending a specially crafted message, causing the MMS service process to terminate and resulting in a denial-of-service (DoS). The vulnerability is addressed in version 1.6.2.
Affected products
- MZ Automation GmbH libiec61850 < 1.6.2
Timeline
- 2026-07-30: advisory
- 2026-07-30: patched