CVE-2019-7670 in FlexAir
Summary
by MITRE
Prima Systems FlexAir devices allow Authenticated Command Injection resulting in Root Remote Code Execution.
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Analysis
by VulDB Data Team • 10/02/2024
The CVE-2019-7670 vulnerability represents a critical command injection flaw affecting Prima Systems FlexAir devices that enables authenticated attackers to execute arbitrary commands with root privileges remotely. This vulnerability exists within the device's web interface authentication mechanism and command processing logic, creating a pathway for malicious actors who have already established legitimate credentials to escalate their privileges and gain complete system control. The flaw stems from insufficient input validation and improper command execution handling within the device's firmware, specifically in how it processes user-supplied parameters during administrative operations. Security researchers identified that the vulnerability allows for command injection attacks through crafted input fields that are not properly sanitized before being passed to system commands. The impact extends beyond simple privilege escalation as the vulnerability provides attackers with complete root access to the underlying operating system, enabling them to modify system files, install malicious software, access sensitive data, and potentially use the compromised device as a pivot point for broader network attacks. This vulnerability directly maps to CWE-77 which describes improper neutralization of special elements used in command execution contexts, and aligns with ATT&CK technique T1059.001 for command and scripting interpreter. The affected Prima Systems FlexAir devices operate on embedded Linux systems where the command injection occurs during administrative tasks such as network configuration, system monitoring, or device management functions. The vulnerability is particularly concerning because it requires only authenticated access, meaning that an attacker who has obtained valid user credentials can exploit this flaw without needing additional privileges or complex attack vectors. The exploitation process typically involves crafting malicious payloads that bypass input sanitization measures and inject operating system commands directly into vulnerable parameters. This creates a significant risk for industrial control systems and network infrastructure devices where such appliances are commonly deployed, as these systems often handle critical network operations and may be located in environments with limited physical security controls. Organizations running these devices face potential data breaches, service disruptions, and compromise of entire network segments if this vulnerability is not addressed promptly.
The operational impact of CVE-2019-7670 extends far beyond immediate system compromise as it enables persistent access and lateral movement within affected networks. Once an attacker achieves root access through this vulnerability, they can establish backdoors, modify system configurations, disable security features, and maintain long-term presence without detection. The vulnerability's exploitation requires minimal technical expertise and can be automated through readily available attack frameworks, making it particularly dangerous for organizations with limited cybersecurity resources. Network administrators may not immediately detect this compromise as the malicious activities can be conducted through legitimate administrative interfaces, blending in with normal system operations. The affected devices often lack robust logging mechanisms or proper audit trails that would help detect unauthorized command execution, further complicating incident response efforts. Organizations should consider implementing network segmentation strategies to limit the potential damage from such compromises, as the vulnerability could enable attackers to move laterally through connected systems. The remediation process requires firmware updates from Prima Systems, which may not be immediately available or compatible with existing device configurations. Security teams must also conduct comprehensive vulnerability assessments to identify all affected devices and implement temporary mitigations such as network access controls or disabling unnecessary administrative interfaces while permanent patches are deployed. The vulnerability's presence in industrial environments raises additional concerns regarding operational technology security, where system uptime and reliability are paramount, and patching activities may be constrained by operational requirements.
Mitigation strategies for CVE-2019-7670 should focus on both immediate defensive measures and long-term security improvements. Organizations should implement network segmentation to isolate affected devices from critical infrastructure and limit the potential blast radius of successful exploitation attempts. Access controls should be strengthened through multi-factor authentication and least privilege principles to reduce the likelihood of unauthorized access. Regular security audits and vulnerability scanning should be conducted to identify similar flaws in other network equipment and industrial control systems. The implementation of web application firewalls and input validation measures can help prevent command injection attempts even if other security controls fail. Network monitoring solutions should be enhanced to detect unusual command execution patterns or unauthorized administrative activities. Security teams should also develop incident response procedures specifically tailored for industrial control system compromises, including protocols for device recovery and forensic analysis. Device vendors should provide clear guidance on patch management and security updates to ensure timely remediation. The vulnerability highlights the importance of secure coding practices in embedded systems and demonstrates the need for regular security assessments of industrial equipment. Organizations should consider adopting zero-trust network architectures where all access requests are continuously validated regardless of network location or previously granted privileges. Additionally, regular security training for personnel responsible for maintaining industrial control systems can help prevent social engineering attacks that might lead to credential compromise. The incident should serve as a catalyst for broader security improvements across industrial environments, emphasizing the critical need for robust security practices in operational technology infrastructure that often receives less attention than traditional IT systems.