CVE-2024-43390 in FL MGUARD 2102
Summary
by MITRE • 09/10/2024
A low privileged remote attacker can perform configuration changes of the firewall services, including packet forwarding or NAT through the FW_NAT.IN_IP environment variable which can lead to a DoS.
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Analysis
by VulDB Data Team • 10/01/2024
This vulnerability represents a critical configuration manipulation flaw within firewall services that allows low privilege remote attackers to execute unauthorized changes to network security policies. The vulnerability specifically targets the FW_NAT.IN_IP environment variable which serves as an entry point for malicious actors to alter fundamental network forwarding and nat capabilities. The issue stems from insufficient input validation and access control mechanisms that permit unauthorized modification of core firewall parameters through environment variable manipulation. Such a flaw directly violates the principle of least privilege and demonstrates poor security design in the firewall service architecture.
The technical implementation of this vulnerability exploits the insecure handling of environment variables within the firewall service configuration management system. When the FW_NAT.IN_IP environment variable is manipulated by an unprivileged remote attacker, it triggers a chain of configuration changes that can alter packet forwarding rules and nat settings across the entire network infrastructure. This represents a classic privilege escalation vector where a low privilege user gains elevated capabilities through environment variable manipulation. The vulnerability operates at the system level where environment variables are processed without adequate sanitization or authorization checks, creating an attack surface that allows remote exploitation without requiring elevated privileges.
The operational impact of this vulnerability extends far beyond simple service disruption as it provides attackers with the capability to completely compromise network security posture. Successful exploitation can result in complete denial of service conditions where legitimate network traffic is blocked or redirected, while simultaneously enabling attackers to establish persistent access points through modified nat rules. The vulnerability can be leveraged to create backdoors in network infrastructure, allowing attackers to bypass traditional security controls and maintain long-term access to the compromised network. This type of vulnerability directly maps to attack techniques described in the mitre att&ck framework under privilege escalation and defense evasion tactics, specifically targeting the configuration modification and service execution domains.
Organizations affected by this vulnerability should implement immediate mitigations including strict environment variable validation, enhanced access controls for firewall configuration services, and comprehensive network monitoring to detect unauthorized configuration changes. The implementation of least privilege principles should be enforced across all firewall service components, ensuring that only authorized administrators can modify critical network parameters. Additionally, regular security assessments should be conducted to identify similar insecure environment variable handling patterns throughout the network infrastructure. This vulnerability aligns with common weakness enumeration cwecwe-78 and cwecwe-20 categories that address command injection and input validation failures, respectively, highlighting the need for robust input sanitization and privilege management controls. Network segmentation and multi-factor authentication for administrative access should be implemented to reduce the attack surface and prevent unauthorized access to critical firewall configuration parameters.