CVE-2020-28331 in wePresent WiPG-1600W
Summary
by MITRE • 11/25/2020
Barco wePresent WiPG-1600W devices have Improper Access Control. Affected Version(s): 2.5.1.8. The Barco wePresent WiPG-1600W device has an SSH daemon included in the firmware image. By default, the SSH daemon is disabled and does not start at system boot. The system initialization scripts read a device configuration file variable to see if the SSH daemon should be started. The web interface does not provide a visible capability to alter this configuration file variable. However, a malicious actor can include this variable in a POST such that the SSH daemon will be started when the device boots.
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Analysis
by VulDB Data Team • 12/09/2020
The Barco wePresent WiPG-1600W device represents a significant security vulnerability through its improper access control implementation that directly impacts the device's authentication and authorization mechanisms. This vulnerability resides within the device's firmware configuration management system where the SSH daemon startup behavior is controlled through a configuration file variable. The device operates under a default security model where the SSH daemon remains disabled at boot time, which is a reasonable security practice. However, the implementation flaw occurs in the web interface's configuration management capabilities, which fails to provide proper access controls for modifying critical security parameters. The vulnerability stems from the device's failure to properly validate and restrict administrative access to system configuration parameters, creating an attack vector that bypasses normal user interface controls.
The technical flaw manifests in the device's system initialization scripts that read configuration variables to determine SSH daemon behavior. When the web interface processes POST requests, it fails to properly validate input parameters against authorized administrative functions. This creates a path where an attacker can inject a configuration variable that enables the SSH daemon to start automatically at boot time. The vulnerability is classified as a weak access control mechanism that allows unauthorized modification of system security parameters through indirect injection methods. This flaw directly relates to CWE-284 which describes improper access control in software systems. The attack vector specifically exploits the device's trust in web interface inputs without proper validation of administrative privileges, making it a prime candidate for privilege escalation attacks.
The operational impact of this vulnerability is substantial as it provides persistent access to the device's management interface through the SSH protocol. Once the SSH daemon is enabled through the configuration variable injection, an attacker gains remote administrative access to the device without requiring physical access or legitimate credentials. This creates a backdoor that remains active across device reboots, enabling long-term access to the network infrastructure. The vulnerability is particularly concerning for environments where these devices are deployed, as they may be located in sensitive areas where unauthorized access could lead to information disclosure or network compromise. The attack scenario follows a typical privilege escalation pattern where an attacker first gains access to the web interface and then uses the configuration injection to enable persistent access, which aligns with ATT&CK technique T1078 for valid accounts and T1566 for credential harvesting.
The mitigation strategy for this vulnerability requires immediate implementation of proper input validation and access control mechanisms within the web interface. Device administrators should disable the SSH daemon functionality until proper authentication controls are implemented and validated. The system should enforce strict validation of all configuration parameters received through web interfaces, implementing proper privilege checks before allowing modification of security-critical settings. Additionally, network segmentation should be implemented to isolate these devices from critical network segments, and monitoring should be enabled to detect unauthorized configuration changes. The vulnerability highlights the importance of implementing proper security controls during the device initialization phase and the need for comprehensive access control validation in all user-facing interfaces. Organizations should also consider implementing firmware update policies that address this specific vulnerability and ensure that all devices are running patched versions. The remediation process should include reviewing all configuration parameters that can be modified through web interfaces and ensuring that proper authentication and authorization controls are in place before allowing any configuration changes that could affect system security.