CVE-2015-2823 in SIMATIC HMI Basic Panel
Summary
by MITRE
Siemens SIMATIC HMI Basic Panels 2nd Generation before WinCC (TIA Portal) 13 SP1 Upd2, SIMATIC HMI Comfort Panels before WinCC (TIA Portal) 13 SP1 Upd2, SIMATIC WinCC Runtime Advanced before WinCC (TIA Portal) 13 SP1 Upd2, SIMATIC WinCC Runtime Professional before WinCC (TIA Portal) 13 SP1 Upd2, SIMATIC HMI Basic Panels 1st Generation (WinCC TIA Portal), SIMATIC HMI Mobile Panel 277 (WinCC TIA Portal), SIMATIC HMI Multi Panels (WinCC TIA Portal), and SIMATIC WinCC 7.x before 7.3 Upd4 allow remote attackers to complete authentication by leveraging knowledge of a password hash without knowledge of the associated password.
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Analysis
by VulDB Data Team • 05/03/2022
The vulnerability described in CVE-2015-2823 represents a critical authentication bypass flaw affecting Siemens HMI (Human Machine Interface) products across multiple generations of their WinCC TIA Portal software ecosystem. This issue impacts a wide range of industrial control systems including Basic Panels 1st and 2nd Generation, Comfort Panels, Mobile Panels, Multi Panels, and various WinCC Runtime editions. The vulnerability stems from a fundamental weakness in the authentication mechanism that allows remote attackers to bypass the normal password-based authentication process by simply knowing a password hash without possessing the actual password, which fundamentally undermines the security model of these industrial control systems.
The technical flaw manifests in the improper handling of authentication credentials within the Siemens HMI software implementations. This vulnerability specifically affects the password verification process where the system accepts pre-computed password hashes as valid authentication tokens, eliminating the need for the actual password. This behavior creates an authentication bypass condition that aligns with CWE-287, which addresses improper handling of authentication tokens. The flaw essentially allows an attacker to perform what is known as a "password hash cracking" attack where they can leverage existing hash values to gain unauthorized access to the system without needing to perform brute force attacks or other password recovery techniques.
The operational impact of this vulnerability is severe for industrial environments relying on Siemens HMI systems, as it provides remote attackers with unauthorized access to critical control systems. This vulnerability enables attackers to gain complete administrative access to the HMI panels, potentially allowing them to modify operational parameters, disrupt industrial processes, or even cause physical damage to equipment. The remote nature of the attack means that adversaries can exploit this vulnerability from outside the corporate network, making it particularly dangerous for industrial control systems that may have limited network segmentation. This aligns with ATT&CK technique T1078.004 which covers valid accounts used for lateral movement and persistence, as the attacker can establish unauthorized access using legitimate authentication mechanisms.
Organizations utilizing affected Siemens HMI products should immediately implement mitigation strategies including applying the relevant software updates from Siemens, which address this vulnerability in WinCC (TIA Portal) 13 SP1 Upd2 and subsequent releases. Network segmentation and access controls should be strengthened to limit remote access to these systems, while monitoring should be implemented to detect unusual authentication patterns. The vulnerability also highlights the importance of secure credential management practices and the need for robust authentication mechanisms in industrial control systems, as outlined in various cybersecurity frameworks including NIST SP 800-82 and IEC 62443 standards. Additionally, organizations should conduct comprehensive vulnerability assessments of their industrial control system environments to identify and remediate similar authentication weaknesses that may exist in other components of their operational technology infrastructure.