CVE-2018-10943 in ClickShare CSE-200
Summary
by MITRE
An issue was discovered on Barco ClickShare CSE-200 and CS-100 Base Units with firmware before 1.6.0.3. Sending an arbitrary unexpected string to TCP port 7100 respecting a certain frequency timing disconnects all clients and results in a crash of the Unit.
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Analysis
by VulDB Data Team • 03/01/2020
The vulnerability identified as CVE-2018-10943 affects Barco ClickShare CSE-200 and CS-100 base units running firmware versions prior to 1.6.0.3, representing a critical denial of service weakness that compromises the availability of collaborative presentation systems. This vulnerability resides within the TCP port 7100 service which handles communication protocols for device management and client connectivity. The flaw manifests when an attacker sends malformed or unexpected string data to this specific port at predetermined timing intervals, creating a condition that systematically disconnects all connected clients and ultimately causes the base unit to crash completely.
The technical nature of this vulnerability stems from inadequate input validation and error handling within the device's network protocol implementation. When the system receives unexpected data patterns on port 7100, it fails to properly sanitize or reject malformed inputs, leading to a cascade of errors that eventually results in system instability and complete service disruption. This behavior aligns with CWE-129, Input Validation, and CWE-242, Use of Insecure Function, as the system processes external inputs without sufficient security checks. The timing aspect of the attack suggests that the vulnerability may be related to buffer overflows or memory corruption issues that occur when the device attempts to parse the malformed data streams at specific intervals, causing memory exhaustion or stack corruption.
The operational impact of this vulnerability extends beyond simple service disruption, as it fundamentally compromises the reliability and security of collaborative environments where these devices are deployed. Organizations relying on Barco ClickShare systems for business presentations, meetings, and collaborative work sessions face significant risks when this vulnerability exists in their infrastructure. The automatic disconnection of all clients creates a cascading failure that can disrupt critical business operations, potentially leading to lost productivity and compromised sensitive meetings. From an attacker perspective, this vulnerability enables a simple yet effective denial of service attack that requires minimal technical expertise to execute, making it particularly dangerous in enterprise environments where such systems are critical to daily operations.
The attack vector for this vulnerability involves sending specifically crafted data packets to TCP port 7100 on the affected devices, with the timing of these packets being crucial for successful exploitation. This timing requirement suggests that the vulnerability may be related to race conditions or specific state machine transitions within the device's communication protocols. The fact that this affects firmware versions prior to 1.6.0.3 indicates that Barco had identified and implemented fixes in their later releases, demonstrating the importance of keeping networked devices updated with the latest security patches. Organizations should consider this vulnerability in their risk assessments and incident response planning, as it could be exploited by both malicious actors seeking to disrupt operations and by automated scanning tools that identify vulnerable systems.
Mitigation strategies for CVE-2018-10943 primarily involve firmware updates to version 1.6.0.3 or later, which would address the underlying input validation issues and implement proper error handling for malformed data. Network administrators should also consider implementing network segmentation to limit access to TCP port 7100, particularly in environments where the devices are exposed to untrusted networks. From a defensive perspective, this vulnerability aligns with ATT&CK technique T1499.004, Network Denial of Service, and represents a classic example of how insufficient input validation can lead to system instability. Organizations should also implement monitoring solutions to detect unusual patterns of network traffic targeting these specific ports and establish incident response procedures for handling potential denial of service events. The vulnerability serves as a reminder of the critical importance of maintaining up-to-date firmware and implementing proper network security controls for collaborative technology systems.