CVE-2011-1563 in RealWin
Summary
by MITRE
Multiple stack-based buffer overflows in the HMI application in DATAC RealFlex RealWin 2.1 (Build 6.1.10.10) and earlier allow remote attackers to execute arbitrary code via (1) a long username in an On_FC_CONNECT_FCS_LOGIN packet, and crafted (2) On_FC_CTAGLIST_FCS_CADDTAG, (3) On_FC_CTAGLIST_FCS_CDELTAG, (4) On_FC_CTAGLIST_FCS_ADDTAGMS, (5) On_FC_RFUSER_FCS_LOGIN, (6) unspecified "On_FC_BINFILE_FCS_*FILE", (7) On_FC_CGETTAG_FCS_GETTELEMETRY, (8) On_FC_CGETTAG_FCS_GETCHANNELTELEMETRY, (9) On_FC_CGETTAG_FCS_SETTELEMETRY, (10) On_FC_CGETTAG_FCS_SETCHANNELTELEMETRY, and (11) On_FC_SCRIPT_FCS_STARTPROG packets to port 910.
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Analysis
by VulDB Data Team • 02/19/2025
The vulnerability identified as CVE-2011-1563 represents a critical stack-based buffer overflow issue within the Human Machine Interface application of DATAC RealFlex RealWin 2.1 and earlier versions. This flaw exists in the communication protocol handling mechanisms of the software, specifically affecting the HMI application that manages industrial control systems. The vulnerability manifests through multiple packet types that are processed by the application when communicating over port 910, making it particularly dangerous as it can be exploited remotely without requiring physical access to the system. The affected software operates in industrial environments where security is paramount, making this vulnerability a significant concern for operational technology infrastructure.
The technical exploitation of this vulnerability occurs through carefully crafted network packets that exceed the allocated buffer space in the application's memory management. The buffer overflow conditions are triggered by sending specially formatted data within various packet types including On_FC_CONNECT_FCS_LOGIN, On_FC_CTAGLIST_FCS_CADDTAG, On_FC_CTAGLIST_FCS_CDELTAG, On_FC_CTAGLIST_FCS_ADDTAGMS, On_FC_RFUSER_FCS_LOGIN, On_FC_BINFILE_FCS_*FILE, On_FC_CGETTAG_FCS_GETTELEMETRY, On_FC_CGETTAG_FCS_GETCHANNELTELEMETRY, On_FC_CGETTAG_FCS_SETTELEMETRY, On_FC_CGETTAG_FCS_SETCHANNELTELEMETRY, and On_FC_SCRIPT_FCS_STARTPROG. These packets all share the common vulnerability of not properly validating input length before copying data into fixed-size buffers, which directly corresponds to CWE-121 Stack-based Buffer Overflow. The flaw allows attackers to overwrite adjacent memory locations including return addresses and function pointers, enabling arbitrary code execution with the privileges of the running application.
The operational impact of this vulnerability extends far beyond simple code execution, as it provides attackers with complete control over the industrial control system's HMI interface. This represents a severe compromise in industrial cybersecurity where unauthorized access could lead to disruption of critical processes, data manipulation, or complete system takeover. The vulnerability affects industrial environments where RealWin is deployed for process control and monitoring, potentially impacting sectors such as manufacturing, power generation, and other critical infrastructure. Attackers could exploit this vulnerability to modify control parameters, alter operational data, or inject malicious commands that could cause physical damage to equipment or compromise safety systems. The remote exploit capability means that attackers do not need to be physically present at the industrial site, making the attack surface significantly larger and more concerning from a security perspective.
The exploitation of this vulnerability aligns with tactics described in the MITRE ATT&CK framework under the initial access and execution phases, specifically targeting the use of remote services and command and control mechanisms. Organizations should implement immediate mitigations including network segmentation to isolate the affected systems from general network access, firewall rules to restrict communication on port 910, and application whitelisting to prevent unauthorized execution. The most effective long-term solution involves updating to a patched version of DATAC RealFlex RealWin, as the vendor would have addressed the buffer overflow conditions through proper input validation and memory management. Additionally, network monitoring should be enhanced to detect anomalous packet patterns that may indicate exploitation attempts, and regular security assessments should be conducted to identify similar vulnerabilities in industrial control system components. Organizations should also consider implementing intrusion detection systems specifically designed for industrial protocols to provide additional layers of defense against such attacks.