CVE-2002-0748 in LabVIEW
Summary
by MITRE
LabVIEW Web Server 5.1.1 through 6.1 allows remote attackers to cause a denial of service (crash) via an HTTP GET request that ends in two newline characters, instead of the expected carriage return/newline combinations.
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Analysis
by VulDB Data Team • 12/20/2024
The vulnerability identified as CVE-2002-0748 affects the LabVIEW Web Server component version 5.1.1 through 6.1, representing a classic buffer handling flaw that can be exploited to trigger a denial of service condition. This issue stems from the server's inadequate processing of HTTP GET requests, specifically when the request terminates with two newline characters rather than the standard carriage return followed by newline sequence. The flaw demonstrates a fundamental weakness in input validation and protocol parsing that existed within National Instruments' web server implementation during this time period. Such vulnerabilities often arise from insufficient sanitization of received data streams, where the application fails to properly normalize or validate the format of incoming communication before processing it.
The technical execution of this vulnerability involves crafting a malicious HTTP GET request that contains a sequence ending with two consecutive newline characters. When the LabVIEW Web Server processes this malformed request, it fails to correctly handle the unexpected termination sequence, leading to a crash or complete service disruption. This behavior typically occurs because the web server's parser does not properly account for various valid HTTP line ending formats, specifically failing to normalize the input to a standard format before proceeding with request handling. The vulnerability directly maps to CWE-129, which addresses improper validation of input boundaries, and CWE-20, which covers inputs that are not properly sanitized, creating a path for malformed data to cause system instability.
From an operational impact perspective, this vulnerability presents a significant risk to systems relying on LabVIEW Web Server for remote access or monitoring capabilities. The denial of service condition effectively renders the web server unavailable to legitimate users, potentially disrupting critical industrial control or data acquisition processes that depend on web-based interfaces. The attack vector is particularly concerning because it requires minimal sophistication to execute, making it accessible to attackers with basic knowledge of HTTP protocols. This vulnerability can be particularly damaging in industrial environments where continuous operation is critical, as the server crash may require manual intervention to restore service, potentially causing extended downtime.
Organizations should implement immediate mitigations including upgrading to patched versions of LabVIEW Web Server where available, or applying network-level firewall rules to restrict access to the affected web server ports. Additionally, implementing input validation at the network perimeter can help filter out malformed requests before they reach the vulnerable server component. The remediation strategy should also include monitoring for unusual patterns in web server access logs that might indicate exploitation attempts. This vulnerability exemplifies the importance of proper protocol handling and input normalization, as outlined in the ATT&CK framework's technique T1499 for network denial of service, where attackers leverage protocol implementation weaknesses to disrupt services. Regular security assessments and vulnerability scanning should be conducted to identify similar issues in legacy systems that may not receive ongoing support or patches from vendors.