CVE-2020-12493 in CPU LS4000
Summary
by MITRE
An open port used for debugging in SWARCOs CPU LS4000 Series with versions starting with G4... grants root access to the device without access control via network. A malicious user could use this vulnerability to get access to the device and disturb operations with connected devices.
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Analysis
by VulDB Data Team • 10/20/2020
The vulnerability described in CVE-2020-12493 represents a critical security flaw in SWARCO's CPU LS4000 Series industrial control devices. This issue manifests through an improperly configured debugging port that remains accessible over the network without any form of authentication or access control mechanisms. The affected devices, specifically those with firmware versions beginning with G4, expose a network service that provides root-level administrative access to the system. This configuration creates a significant attack surface that allows remote exploitation without the need for credentials or privileged access.
The technical implementation of this vulnerability stems from the default configuration of the debugging interface within the SWARCO LS4000 Series controllers. The debugging port operates on a network socket that accepts connections from any remote address without requiring authentication, authorization, or encryption. This design flaw aligns with CWE-284, which addresses improper access control issues in software systems. The vulnerability exists at the network protocol level where the debugging service is bound to a well-known port and listens for incoming connections without implementing any form of authentication checks or access restriction mechanisms. The root access granted through this interface provides attackers with complete control over the device's operating system, including the ability to modify system files, install malicious software, and manipulate the device's operational parameters.
From an operational perspective, this vulnerability poses severe risks to industrial control systems and critical infrastructure environments where SWARCO devices are deployed. The impact extends beyond simple unauthorized access to include potential disruption of connected systems, manipulation of control processes, and compromise of operational integrity. Attackers could leverage this vulnerability to cause denial of service conditions, alter control parameters, or even execute arbitrary code on the affected devices. The consequences could be particularly devastating in transportation systems, power grid control centers, or manufacturing environments where these controllers manage critical processes. According to ATT&CK framework, this vulnerability maps to T1071.004 for application layer protocols and T1068 for exploit for privilege escalation, demonstrating how attackers can move laterally within industrial networks and escalate their privileges to full system control.
The mitigation strategies for this vulnerability require immediate implementation of network segmentation and access control measures. Organizations should disable or disable the debugging port entirely through firmware updates or configuration changes, as SWARCO has released patches addressing this specific issue. Network administrators must implement firewall rules that block access to the debugging port from unauthorized networks and ensure that only trusted administrative workstations can connect to these services. Additionally, continuous monitoring of network traffic should be implemented to detect any unauthorized access attempts to the debugging interface. The vulnerability highlights the importance of secure configuration management in industrial environments and underscores the need for regular security assessments of operational technology systems. Organizations should also consider implementing network access control solutions and regular vulnerability scanning to identify similar misconfigurations across their industrial control system infrastructure.