CVE-2015-0997 in InduSoft Web Studio
Summary
by MITRE
Schneider Electric InduSoft Web Studio before 7.1.3.4 SP3 Patch 4 and InTouch Machine Edition 2014 before 7.1.3.4 SP3 Patch 4 provide an HMI user interface that lists all valid usernames, which makes it easier for remote attackers to obtain access via a brute-force password-guessing attack.
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Analysis
by VulDB Data Team • 06/28/2017
The vulnerability identified as CVE-2015-0997 affects Schneider Electric InduSoft Web Studio and InTouch Machine Edition software versions prior to specific patch releases. This security flaw represents a critical weakness in authentication mechanisms that exposes valid username information to remote attackers. The vulnerability specifically impacts human machine interface systems that are commonly deployed in industrial control environments where security is paramount. The flaw allows unauthorized parties to enumerate valid user accounts through the HMI interface, creating an attack surface that significantly reduces the difficulty of subsequent authentication attempts.
The technical implementation of this vulnerability stems from the software's failure to properly handle user account enumeration during authentication processes. When attempting to log in to the system, the application provides distinct error messages or response patterns that indicate whether a username exists in the system. This behavior directly violates security best practices by exposing account information that should remain confidential during authentication attempts. The vulnerability operates at the application layer and can be exploited remotely without requiring prior authentication or specialized equipment. This characteristic makes it particularly dangerous in industrial environments where these systems may be directly accessible from external networks.
The operational impact of this vulnerability extends beyond simple credential theft, as it enables sophisticated brute-force attacks that can systematically test password combinations against valid user accounts. Attackers can leverage this information to conduct targeted password-guessing campaigns that are orders of magnitude more effective than random attempts. The exposure of valid usernames creates a significant advantage for threat actors attempting to compromise industrial control systems, which often contain critical infrastructure components. This vulnerability directly relates to CWE-200, which addresses information exposure, and represents a clear violation of the principle of least privilege in authentication systems. The consequences can be severe in industrial settings where system compromise could lead to operational disruption, safety hazards, or unauthorized access to critical processes.
Mitigation strategies for this vulnerability require immediate implementation of software updates to the affected versions of InduSoft Web Studio and InTouch Machine Edition. Organizations should ensure that all systems are updated to version 7.1.3.4 SP3 Patch 4 or later, which addresses the username enumeration issue through improved authentication response handling. Network segmentation should be implemented to limit access to these industrial systems from untrusted networks, and access controls should be enforced through multi-factor authentication mechanisms where possible. Security monitoring should be enhanced to detect unusual authentication patterns that might indicate brute-force attack attempts. Additionally, organizations should conduct comprehensive vulnerability assessments of their industrial control systems to identify similar information disclosure vulnerabilities that could provide attackers with additional attack vectors. The remediation process should include configuration reviews to ensure that authentication systems are properly hardened against account enumeration attacks, and that error messages do not provide detailed information about authentication failures to potential attackers. This vulnerability demonstrates the critical importance of maintaining up-to-date security patches in industrial control environments where the stakes of system compromise are particularly high.