CVE-2011-4876 in SIMATIC HMI panel
Summary
by MITRE
Directory traversal vulnerability in HmiLoad in the runtime loader in Siemens WinCC flexible 2004, 2005, 2007, and 2008; WinCC V11 (aka TIA portal); the TP, OP, MP, Comfort Panels, and Mobile Panels SIMATIC HMI panels; WinCC V11 Runtime Advanced; and WinCC flexible Runtime, when Transfer Mode is enabled, allows remote attackers to execute, read, create, modify, or delete arbitrary files via a .. (dot dot) in a string.
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Analysis
by VulDB Data Team • 04/10/2025
The CVE-2011-4876 vulnerability represents a critical directory traversal flaw within Siemens WinCC flexible runtime environments and related HMI panel systems. This vulnerability exists in the HmiLoad component of the runtime loader across multiple Siemens products including WinCC flexible 2004 through 2008 versions, WinCC V11 (TIA Portal), various SIMATIC HMI panels, and WinCC V11 Runtime Advanced. The flaw manifests when Transfer Mode is enabled, creating a pathway for remote attackers to manipulate file system operations through crafted directory traversal sequences using the .. (dot dot) notation. The vulnerability stems from inadequate input validation and path sanitization within the file handling mechanisms of these industrial automation systems.
The technical exploitation of this vulnerability occurs through the manipulation of file path strings that contain directory traversal sequences, allowing attackers to bypass normal file access controls. When Transfer Mode is active, the system processes user-supplied strings without proper validation of directory traversal components, enabling attackers to navigate outside the intended directory boundaries. This flaw specifically affects the HmiLoad runtime loader component which handles file operations for HMI panel configurations and runtime data. The vulnerability is classified under CWE-22 as Improper Limitation of a Pathname to a Restricted Directory, a well-known weakness in file system access control mechanisms. Attackers can leverage this vulnerability to execute arbitrary code by placing malicious files in strategic locations, read sensitive configuration data, create new files with elevated privileges, modify existing system files, or delete critical runtime components. The attack vector is remote, meaning no physical access or local credentials are required to exploit the vulnerability.
The operational impact of CVE-2011-4876 is particularly severe in industrial control environments where Siemens WinCC systems are deployed for critical infrastructure monitoring and control. The ability to execute arbitrary file operations on HMI panels and runtime systems can lead to complete system compromise, operational disruption, and potential safety hazards in industrial processes. Attackers could modify configuration files to alter control logic, create backdoor access points, or corrupt runtime data that affects the proper functioning of industrial processes. The vulnerability affects both the desktop versions of WinCC flexible and the runtime environments on various HMI panels including TP, OP, MP, Comfort Panels, and Mobile Panels. This creates a widespread attack surface across multiple product lines and deployment scenarios within industrial automation environments. The vulnerability's presence in WinCC V11 (TIA Portal) and related runtime components indicates this flaw affects both legacy systems and newer industrial automation platforms, making it particularly concerning for organizations with mixed system environments.
Organizations affected by this vulnerability should implement immediate mitigations including disabling Transfer Mode when not required, implementing network segmentation to limit access to HMI systems, and applying available vendor patches or firmware updates. The vulnerability aligns with ATT&CK technique T1059.007 for Command and Scripting Interpreter and T1566.001 for Phishing, as attackers could use this vulnerability to establish persistent access through file manipulation. Additionally, the vulnerability relates to T1547.001 for Registry Run Keys and T1078.004 for Valid Accounts, as attackers could modify system files to establish persistence or escalate privileges. Security monitoring should focus on unusual file access patterns, unauthorized file creation or modification, and network traffic to HMI systems during transfer operations. System administrators should conduct thorough vulnerability assessments across all WinCC installations and implement proper access controls to limit who can configure Transfer Mode settings. The remediation approach should include both immediate network-level controls and long-term architectural improvements to reduce the attack surface of industrial control systems.