CVE-2019-10967 in Ovation OCR400 Controller
Summary
by MITRE
In Emerson Ovation OCR400 Controller 3.3.1 and earlier, a stack-based buffer overflow vulnerability in the embedded third-party FTP server involves improper handling of a long file name from the LIST command to the FTP service, which may cause the service to overwrite buffers, leading to remote code execution and escalation of privileges.
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Analysis
by VulDB Data Team • 09/24/2023
The CVE-2019-10967 vulnerability affects the Emerson Ovation OCR400 Controller version 3.3.1 and earlier, representing a critical stack-based buffer overflow flaw within the embedded third-party FTP server component. This vulnerability stems from inadequate input validation when processing file names during FTP LIST command execution, creating a condition where maliciously crafted long file names can trigger memory corruption. The flaw exists in the embedded FTP service that operates within the industrial control system environment, making it particularly dangerous for operational technology infrastructure. The vulnerability demonstrates a classic improper input handling issue that violates fundamental security principles for memory safety and input validation.
The technical implementation of this vulnerability involves a stack-based buffer overflow that occurs when the embedded FTP server processes a LIST command containing an excessively long file name parameter. When the FTP service attempts to store this extended filename in a fixed-size buffer allocated on the stack, the excessive input overflows into adjacent memory locations, potentially corrupting the stack frame and control data. This memory corruption can overwrite return addresses, function pointers, and other critical execution context information, providing attackers with the ability to redirect program execution flow. The vulnerability is classified as a CWE-121 stack-based buffer overflow, which directly maps to the ATT&CK technique T1059.007 for command and scripting interpreter, as successful exploitation would enable remote code execution within the controller's operational environment.
The operational impact of this vulnerability extends beyond simple service disruption to encompass full system compromise and potential industrial control system compromise. An attacker exploiting this vulnerability could achieve remote code execution with the privileges of the FTP service account, which typically operates with elevated system permissions within the controller environment. This privilege escalation capability allows for complete system takeover, enabling attackers to modify control parameters, access sensitive operational data, and potentially disrupt critical manufacturing processes. The embedded nature of the vulnerable FTP server within the industrial control system makes it particularly concerning as it operates in environments where system availability and integrity are paramount for safety and operational continuity. The vulnerability affects not just the FTP service but the entire controller system, creating a potential attack vector for broader industrial network compromise.
Mitigation strategies for CVE-2019-10967 should prioritize immediate firmware updates from Emerson to address the underlying buffer overflow condition in the embedded FTP server component. Organizations should implement network segmentation to isolate the affected controllers from general network access, reducing the attack surface and limiting potential exploitation paths. Access controls should be strengthened through mandatory authentication for FTP services and implementation of network access control lists to restrict FTP service access to authorized personnel only. Additionally, monitoring and logging should be enhanced to detect anomalous FTP LIST command usage patterns that might indicate exploitation attempts. The vulnerability highlights the importance of secure coding practices and input validation in embedded systems, particularly those operating in industrial control environments where security and safety are critical requirements. Organizations should also consider implementing intrusion detection systems specifically designed to monitor for FTP protocol anomalies and buffer overflow patterns in industrial control network traffic.