CVE-2016-7114 in SIPROTEC
Summary
by MITRE
The EN100 Ethernet module before 4.29 for Siemens SIPROTEC 4 and SIPROTEC Compact devices allows remote attackers to bypass authentication and obtain administrative access via unspecified HTTP traffic during an authenticated session.
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Analysis
by VulDB Data Team • 09/14/2022
The CVE-2016-7114 vulnerability affects Siemens SIPROTEC 4 and SIPROTEC Compact protective relays that utilize the EN100 Ethernet module version 4.28 and earlier. This critical authentication bypass flaw enables remote attackers to gain administrative privileges without proper credentials, representing a significant security risk for industrial control systems. The vulnerability specifically manifests during HTTP traffic processing within authenticated sessions, creating a window of opportunity for malicious actors to escalate their privileges. The affected devices operate in critical infrastructure environments including power generation, transmission, and distribution systems where unauthorized access could lead to severe operational disruptions and safety hazards. This vulnerability directly impacts the integrity and availability of industrial automation systems, potentially allowing attackers to modify protective relay settings, disable safety mechanisms, or manipulate operational parameters that govern electrical power systems.
The technical implementation of this vulnerability stems from insufficient session management and authentication validation within the EN100 Ethernet module's HTTP processing stack. Attackers can exploit this weakness by crafting specific HTTP requests that manipulate the session state, effectively allowing them to bypass the normal authentication procedures that should prevent unauthorized administrative access. The flaw exists in how the system handles session tokens and authentication state transitions during active HTTP communications, creating a path for privilege escalation without requiring valid credentials. This type of vulnerability aligns with CWE-287 which addresses improper authentication issues in software systems. The exploitation requires network access to the affected devices and can be executed remotely, making it particularly dangerous in connected industrial environments where physical security measures may be insufficient to prevent network-based attacks.
The operational impact of CVE-2016-7114 extends beyond simple unauthorized access, as it fundamentally compromises the security posture of critical infrastructure systems. Industrial control systems protected by these devices could face manipulation of protective relay functions, potentially leading to power outages, equipment damage, or safety incidents. The vulnerability's remote exploitability means that attackers do not require physical access to the devices, significantly expanding the attack surface. Organizations using affected Siemens equipment face potential regulatory compliance issues under standards such as NIST SP 800-82, which governs the security of industrial control systems. The attack vector aligns with ATT&CK technique T1078 for valid accounts and T1566 for credential harvesting, as attackers can leverage this vulnerability to establish persistent administrative access. The impact is particularly severe in critical infrastructure environments where these protective relays form the backbone of electrical system protection, making any compromise potentially catastrophic for operational continuity and public safety.
Organizations should immediately implement mitigations including firmware updates to version 4.29 or later of the EN100 Ethernet module, which addresses the authentication bypass vulnerability. Network segmentation should be implemented to isolate affected devices from general network access, reducing the attack surface available to potential adversaries. Additional security controls such as network access control lists, intrusion detection systems, and regular security monitoring should be deployed to detect potential exploitation attempts. The vulnerability requires careful consideration of operational impacts during patching, as industrial control systems often operate in environments where downtime is costly and requires careful planning. Security teams should conduct comprehensive vulnerability assessments to identify all affected devices within their infrastructure and implement network-based controls to prevent unauthorized access to these critical systems. Regular security audits and penetration testing should be performed to validate the effectiveness of implemented controls and identify additional vulnerabilities that may exist within the industrial control system environment.