CVE-2019-6719 in libIEC61850
Summary
by MITRE
An issue has been found in libIEC61850 v1.3.1. There is a use-after-free in the getState function in mms/iso_server/iso_server.c, as demonstrated by examples/server_example_goose/server_example_goose.c and examples/server_example_61400_25/server_example_61400_25.c.
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Analysis
by VulDB Data Team • 07/03/2023
The vulnerability identified as CVE-2019-6719 represents a critical use-after-free condition within the libIEC61850 library version 1.3.1, specifically affecting the getState function implementation in the mms/iso_server/iso_server.c file. This library serves as a fundamental component for implementing IEC 61850 communication protocols in substation automation systems, which are critical infrastructure components in power grid operations. The flaw manifests when the getState function processes certain MMS (Manufacturing Message Specification) requests, creating a scenario where memory previously freed to the heap is accessed, potentially leading to arbitrary code execution or system instability.
The technical exploitation of this vulnerability occurs through improper memory management within the server example implementations, particularly in the server_example_goose.c and server_example_61400_25.c files. When these examples handle specific communication patterns or data structures, the getState function fails to properly validate memory references before accessing them, creating a window where freed memory blocks can be reused or accessed by subsequent operations. This memory corruption vulnerability falls under CWE-416, which specifically addresses Use After Free conditions, where a pointer is used after the memory it points to has been freed, and aligns with ATT&CK technique T1059.007 for command and scripting interpreter, as exploitation could enable remote code execution through manipulated communication protocols.
The operational impact of this vulnerability extends beyond simple memory corruption, as it affects the reliability and security of substation automation systems that rely on IEC 61850 standards for communication between protective relays, control systems, and monitoring equipment. Attackers could potentially exploit this vulnerability to disrupt power grid operations, gain unauthorized access to critical infrastructure, or cause cascading failures in electrical systems. The vulnerability is particularly concerning because it affects the core communication layer of these systems, making it a prime target for sophisticated attacks targeting industrial control systems. The use of the library in server implementations means that any system running these examples is potentially exposed to remote exploitation, creating a significant risk for utility companies and industrial organizations that depend on these protocols for grid management and protection.
Mitigation strategies for CVE-2019-6719 should prioritize immediate patching of the libIEC61850 library to version 1.4.0 or later, where the memory management issues have been resolved. Organizations should also implement network segmentation and access controls to limit exposure of systems running these server examples to untrusted networks. Additionally, monitoring for unusual communication patterns or unexpected memory usage in IEC 61850 implementations can help detect potential exploitation attempts. The vulnerability highlights the importance of proper memory management in industrial control system software and underscores the need for thorough security testing of communication libraries used in critical infrastructure environments. Security teams should also consider implementing intrusion detection systems specifically tuned to detect exploitation attempts targeting IEC 61850 protocols and related industrial communication standards.