CVE-2004-2315 in AppWeb HTTP Server
Summary
by MITRE
Mbedthis AppWeb HTTP server before 1.0.2 allows remote attackers to cause a denial of service (crash) via an empty OPTIONS request.
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Analysis
by VulDB Data Team • 06/23/2018
The vulnerability identified as CVE-2004-2315 affects Mbedthis AppWeb HTTP server versions prior to 1.0.2, presenting a significant denial of service risk that can be exploited by remote attackers. This issue manifests through specifically crafted empty OPTIONS requests that cause the server to crash and become unavailable to legitimate users. The vulnerability represents a fundamental flaw in the server's request handling mechanism, where the application fails to properly validate or process empty OPTIONS HTTP method requests, leading to an unhandled exception that terminates the service.
From a technical perspective, the flaw resides in the server's HTTP protocol implementation where the OPTIONS method is not adequately sanitized or validated when received without any request body or headers. This type of vulnerability falls under CWE-20, which describes improper input validation, and specifically relates to CWE-400, which covers resource exhaustion or uncontrolled resource consumption. The attack vector is particularly concerning because OPTIONS requests are legitimate HTTP methods used for determining the communication options available for a specific resource, making the exploitation appear benign and potentially difficult to distinguish from normal traffic patterns. The vulnerability is classified as a remote attack since no local access is required, and attackers can leverage this weakness from any network location to disrupt service availability.
The operational impact of CVE-2004-2315 extends beyond simple service disruption, as it can be weaponized to create persistent availability issues for web applications relying on the affected server. This vulnerability directly impacts the availability component of the CIA triad, potentially allowing attackers to render web services inaccessible to legitimate users and can be combined with other techniques to create more sophisticated attack scenarios. The crash occurs at the application level rather than the network level, meaning that even if network infrastructure remains intact, the application itself becomes unresponsive. This makes the vulnerability particularly dangerous in environments where uptime is critical, as the server will need to be manually restarted or may require system-level intervention to restore functionality.
Mitigation strategies for this vulnerability should prioritize immediate patching of the Mbedthis AppWeb server to version 1.0.2 or later, which contains the necessary code fixes to properly handle empty OPTIONS requests. Network administrators should implement rate limiting and connection monitoring to detect unusual patterns of OPTIONS requests that may indicate attempted exploitation. Additionally, implementing proper input validation at the server level and configuring appropriate timeouts can help prevent the server from becoming unresponsive. From an ATT&CK framework perspective, this vulnerability aligns with techniques such as T1499.004 for network denial of service and T1566.001 for phishing with malicious attachments, though the primary concern here is the direct availability impact rather than indirect exploitation. Organizations should also consider implementing intrusion detection systems that can identify and alert on suspicious OPTIONS request patterns, as well as maintaining regular vulnerability assessments to identify similar weaknesses in other web server implementations.