CVE-2016-8673 in SIMATIC CP 343-1
Summary
by MITRE
A vulnerability has been identified in SIMATIC CP 343-1 Advanced (incl. SIPLUS NET variant) (All versions < V3.0.53), SIMATIC CP 443-1 Advanced (incl. SIPLUS NET variant) (All versions < V3.2.17), SIMATIC S7-300 PN/DP CPU family (incl. SIPLUS variants) (All versions), SIMATIC S7-400 PN/DP CPU family (incl. SIPLUS variants) (All versions). The integrated web server at port 80/TCP or port 443/TCP of the affected devices could allow remote attackers to perform actions with the permissions of an authenticated user, provided the targeted user has an active session and is induced to trigger the malicious request.
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Analysis
by VulDB Data Team • 10/04/2022
This vulnerability affects Siemens industrial control systems including SIMATIC CP 343-1 and CP 443-1 Advanced communication processors along with various S7-300 and S7-400 CPU families. The flaw resides in the integrated web server implementation that operates on standard TCP ports 80 and 443, creating a significant security risk for industrial environments. The vulnerability stems from insufficient input validation and improper access control mechanisms within the web server component, allowing remote attackers to exploit a session management weakness. This particular issue represents a classic case of insufficient authorization checks and potentially leads to privilege escalation scenarios where unauthenticated attackers could manipulate authenticated sessions. The vulnerability aligns with CWE-285 which addresses improper authorization in web applications and specifically relates to CWE-352 which covers Cross-Site Request Forgery (CSRF) attacks. From an operational perspective, this vulnerability poses a severe threat to industrial control systems since it could enable attackers to perform administrative actions on critical infrastructure equipment without proper authentication. The attack requires minimal prerequisites as the target user must simply have an active session, making it particularly dangerous in operational technology environments where users often maintain persistent connections for system monitoring and configuration purposes.
The technical exploitation of this vulnerability occurs through carefully crafted web requests that leverage existing authenticated sessions to execute unauthorized operations on the affected devices. Attackers could potentially modify system configurations, access sensitive operational data, or even disrupt industrial processes by manipulating the web server interface. This particular weakness enables a form of session hijacking or session manipulation that bypasses normal authentication mechanisms, effectively allowing attackers to operate with the privileges of legitimate users who have active sessions. The impact extends beyond simple data access as these industrial controllers often manage critical process control functions where unauthorized modifications could lead to production disruptions, safety hazards, or security breaches. The vulnerability demonstrates poor implementation of web application security controls and reflects inadequate security testing of industrial communication equipment. The affected devices operate in environments where network segmentation is often limited or absent, making the exploitation of such web server vulnerabilities particularly dangerous. According to ATT&CK framework, this vulnerability maps to T1190 - Exploit Public-Facing Application and T1071.004 - Application Layer Protocol: DNS, as attackers could leverage the web interface to perform reconnaissance and establish further footholds within industrial networks.
Organizations should implement immediate mitigations including applying the latest firmware updates from Siemens which address the specific session management flaws in the affected web server implementations. Network segmentation should be enforced to isolate these devices from general network access, particularly by blocking external access to TCP ports 80 and 443. Administrators should implement strong authentication mechanisms including multi-factor authentication for any remaining web access points and ensure that users maintain short session timeouts to minimize the window of opportunity for exploitation. Regular security assessments of industrial control systems should include web application security testing to identify similar vulnerabilities in other components. The vulnerability highlights the need for robust security practices in industrial environments where legacy systems often lack proper security controls. Organizations should also consider implementing network monitoring solutions to detect anomalous web server traffic patterns that could indicate exploitation attempts. Additionally, the use of secure remote access solutions such as virtual private networks or dedicated industrial security appliances should replace direct web server access where possible. The security community has identified this as a critical vulnerability requiring immediate attention due to its potential for causing operational disruptions in industrial environments where these devices are commonly deployed. The vulnerability's exploitation potential makes it particularly concerning for critical infrastructure sectors including energy, water, and manufacturing where Siemens equipment is widely used. Proper patch management procedures should be established to ensure timely deployment of security updates across all industrial control system components.