CVE-2007-2415 in Web Server
Summary
by MITRE
Pi3Web Web Server 2.0.3 PL1 allows remote attackers to cause a denial of service (application exit) via a long URI. NOTE: this issue was originally reported as a crash, but the vendor states that the impact is a "clean" exit in which "the server I/O loop finishes and the process exits normally."
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Analysis
by VulDB Data Team • 10/14/2017
The vulnerability identified as CVE-2007-2415 affects Pi3Web Web Server version 2.0.3 PL1 and represents a denial of service condition that can be triggered remotely by attackers. This issue stems from the server's inadequate handling of excessively long Uniform Resource Identifiers within HTTP requests. The flaw manifests when a remote attacker crafts a malicious HTTP request containing an abnormally long URI that exceeds the server's expected parameter length limits. The vulnerability operates at the application layer of the network stack, specifically targeting the web server's request processing mechanism.
The technical implementation of this vulnerability involves the web server's failure to properly validate or limit the length of URIs received in HTTP requests. When Pi3Web encounters a request with an overly long URI, its internal processing logic becomes overwhelmed or encounters a condition that causes the server's I/O loop to complete normally but results in the process terminating. This behavior, while described as a "clean" exit by the vendor, effectively constitutes a denial of service since legitimate users cannot access the web server's services during the downtime. The flaw demonstrates poor input validation practices and inadequate resource management within the web server's request handling code, which is classified under CWE-129 as Improper Validation of Array Index and CWE-770 as Allocation of Resources Without Limits or Throttling.
From an operational perspective, this vulnerability presents significant risk to organizations relying on Pi3Web as their web server solution, particularly in environments where continuous availability is critical. The remote exploitation capability means that attackers can potentially disrupt services without requiring physical access or local privileges, making it a particularly dangerous vulnerability for public-facing web servers. The impact extends beyond simple service interruption as it can be used as part of larger attack campaigns or as a precursor to more sophisticated exploitation attempts. Security practitioners should consider this vulnerability in the context of the MITRE ATT&CK framework, specifically under the T1499.004 technique for Network Denial of Service and T1566.001 for Pre-Attack phase techniques involving initial access vectors.
The mitigation strategies for this vulnerability should include immediate implementation of URI length restrictions within the web server configuration, applying the vendor's patch or upgrade to a version that addresses this issue, and implementing network-level controls such as firewall rules or intrusion prevention systems that can detect and block unusually long HTTP requests. Organizations should also consider deploying web application firewalls that can provide additional layers of protection against malformed requests. Regular security assessments and vulnerability scanning should be conducted to identify similar issues in other web server implementations, as this type of input validation flaw is commonly found in legacy web server software. The vulnerability serves as a reminder of the importance of robust input validation and resource management in server applications, particularly in older software versions that may not have been designed with modern security considerations in mind.