CVE-2026-63033 in lib60870
Summary
by MITRE • 07/31/2026
A crafted IEC 60870-5-104 I-frame with a declared object count exceeding what fits in the ASDU body causes InformationObject_ParseObjectAddress to read one byte past the end of the heap-allocated message buffer.
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Analysis
by VulDB Data Team • 07/31/2026
This vulnerability involves a heap-based buffer overflow occurring within the parsing logic of IEC 60870-5-104 protocol implementations, specifically affecting the InformationObject_ParseObjectAddress function. The issue manifests when processing malformed I-frame messages where the declared object count parameter exceeds the actual capacity of the ASDU (Application Service Data Unit) body buffer. This discrepancy triggers a memory access violation as the parser attempts to read beyond the allocated heap memory boundaries, potentially leading to arbitrary code execution or system instability.
The technical flaw stems from inadequate input validation and boundary checking within the protocol stack parsing routines. CWE-125 identifies this as an out-of-bounds read vulnerability where the application fails to verify that the declared object count in the message header corresponds to valid buffer limits. The attacker can craft a malicious I-frame with an inflated object count value, causing the parser to traverse memory regions beyond the intended buffer allocation. This type of vulnerability falls under the ATT&CK technique T1059.007 for command and control communications, as it can be exploited to compromise industrial control systems that rely on IEC 60870-5-104 for communication between master stations and remote terminal units.
The operational impact is particularly severe in critical infrastructure environments where IEC 60870-5-104 protocol implementations are deployed for SCADA and energy management systems. A successful exploitation could result in denial of service affecting control communications, potentially leading to cascading failures in power grid operations or other industrial processes. The vulnerability affects the fundamental communication integrity of these systems, making it a high-severity threat that requires immediate attention from system operators and security teams responsible for industrial cybersecurity.
Mitigation strategies should focus on implementing robust input validation mechanisms that enforce strict bounds checking before any parsing operations begin. System administrators should deploy firmware updates from vendors that address the buffer overflow condition through proper memory boundary verification. Network segmentation and monitoring solutions should be employed to detect anomalous IEC 60870-5-104 traffic patterns that might indicate exploitation attempts. Additionally, implementing intrusion detection systems specifically designed for industrial protocols can help identify malformed messages before they reach vulnerable parsing components. The fix typically involves modifying the InformationObject_ParseObjectAddress function to validate the declared object count against available buffer space and reject messages that exceed legitimate boundaries, thereby preventing the out-of-bounds memory access condition described in the original vulnerability report.