CVE-2000-1038 in AS400 Firewall
Summary
by MITRE
The web administration interface for IBM AS/400 Firewall allows remote attackers to cause a denial of service via an empty GET request.
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Analysis
by VulDB Data Team • 07/27/2019
The vulnerability identified as CVE-2000-1038 affects the web administration interface of IBM AS/400 Firewall, representing a significant security flaw that enables remote attackers to disrupt service availability. This issue manifests through the processing of empty GET requests, which can be exploited to trigger a denial of service condition that impacts the firewall's operational integrity and accessibility. The IBM AS/400 Firewall serves as a critical network security component designed to protect enterprise systems from unauthorized access and malicious traffic, making this vulnerability particularly concerning for organizations relying on this platform for their security infrastructure.
The technical flaw stems from inadequate input validation within the web administration interface implementation. When the firewall receives an empty GET request, the system fails to properly handle this malformed input, leading to a service disruption that effectively renders the administrative interface unavailable to legitimate users. This behavior indicates a lack of proper error handling and request validation mechanisms within the web server component of the firewall system. The vulnerability operates at the application layer and demonstrates weaknesses in the firewall's ability to gracefully manage unexpected or malformed HTTP requests, which is a fundamental requirement for secure network services. According to CWE standards, this represents a weakness categorized under CWE-20: Improper Input Validation, where insufficient validation of input data leads to system instability and potential service disruption.
The operational impact of this vulnerability extends beyond simple service interruption, as it can severely compromise an organization's ability to manage and monitor their firewall configuration. Administrators lose access to critical management functions during an attack, potentially leaving the network exposed to other threats while they attempt to restore service. This vulnerability particularly affects enterprise environments where the IBM AS/400 Firewall is deployed as a primary security control, as the denial of service can occur without requiring authentication or specialized knowledge of the system. The attack vector is particularly dangerous because it can be executed remotely, meaning that adversaries do not need physical access to the system or network to exploit the flaw, making it a significant risk for organizations with exposed firewall management interfaces.
Organizations should implement immediate mitigations including network segmentation to limit access to firewall administrative interfaces, deployment of intrusion detection systems to monitor for suspicious GET requests, and configuration of access control lists to restrict administrative access to trusted network segments only. The implementation of web application firewalls can provide additional protection against malformed requests, while regular monitoring of system logs should be established to detect potential exploitation attempts. According to ATT&CK framework, this vulnerability aligns with techniques categorized under T1499: Endpoint Denial of Service, where adversaries target system resources to prevent legitimate use. Organizations should also consider implementing rate limiting on administrative interfaces to prevent rapid exploitation and establish incident response procedures specifically addressing denial of service attacks targeting security infrastructure components. Regular security assessments and vulnerability scanning should include verification of input validation mechanisms within web applications to prevent similar issues from remaining undetected in other system components.