CVE-2018-11449 in M875
Summary
by MITRE
A vulnerability has been identified in SCALANCE M875 (All versions). An attacker with access to the local file system might obtain passwords for administratrive users. Successful exploitation requires read access to files on the local file system. A successful attack could allow an attacker to obtain administrative passwords. At the time of advisory publication no public exploitation of this security vulnerability was known.
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Analysis
by VulDB Data Team • 03/29/2023
The SCALANCE M875 is a network switch device manufactured by Siemens, designed for industrial automation environments where reliable network connectivity is essential for operational technology systems. This device operates within critical infrastructure settings where security breaches can have severe operational consequences. The vulnerability classified as CVE-2018-11449 represents a significant concern for industrial control systems and supervisory control and data acquisition networks that rely on such equipment for network management and communication. The affected device is part of Siemens' SCALANCE M series, which is commonly deployed in manufacturing environments, power generation facilities, and other industrial settings where network reliability and security are paramount. The vulnerability specifically targets the device's handling of administrative credentials within its local file system.
The technical flaw in CVE-2018-11449 stems from inadequate access controls and privilege separation mechanisms within the SCALANCE M875 device. When an attacker gains read access to the local file system, they can directly access and extract administrative passwords stored in cleartext or weakly encrypted formats within system files. This represents a classic privilege escalation vulnerability where local file system access translates directly into administrative access. The vulnerability is categorized under CWE-276 which deals with incorrect access control, specifically focusing on inadequate file permissions and privilege management. The device's failure to properly protect sensitive credential files demonstrates a fundamental flaw in the principle of least privilege, where administrative credentials are stored in locations accessible to any user with local file system read privileges.
The operational impact of this vulnerability extends beyond simple credential theft, as it provides attackers with full administrative control over the network switch. This level of access enables attackers to modify network configurations, implement man-in-the-middle attacks, disrupt network communications, and potentially escalate their access to other systems within the industrial network. The attack vector requires only local file system read access, which can be achieved through various means including physical access to the device, exploitation of other vulnerabilities that grant local access, or through compromised user accounts with local privileges. The lack of public exploitation at the time of advisory publication does not diminish the severity, as the vulnerability creates a persistent backdoor that can be exploited by any attacker with local access. This vulnerability directly relates to ATT&CK technique T1078 which covers valid accounts and privilege escalation through access to legitimate credentials.
Mitigation strategies for CVE-2018-11449 must focus on both immediate protective measures and long-term architectural improvements. Organizations should implement strict physical security controls to prevent unauthorized access to the device, including locked enclosures, restricted access areas, and proper visitor management protocols. Network segmentation should be employed to limit the blast radius of potential attacks, ensuring that even if one device is compromised, the attacker cannot easily move laterally through the network. The device should be configured with minimal necessary privileges, and administrative accounts should be protected with strong authentication mechanisms including multi-factor authentication where possible. Regular security audits should verify that sensitive files are properly protected with appropriate file permissions and that no unnecessary local access is granted to users or processes. Additionally, implementing network monitoring solutions can help detect unauthorized access attempts or suspicious activities that might indicate exploitation of this vulnerability. System updates and patches should be applied promptly when available, as Siemens would have provided remediation for this vulnerability in their security advisory.