CVE-2006-1547 in Struts
Summary
by MITRE
ActionForm in Apache Software Foundation (ASF) Struts before 1.2.9 with BeanUtils 1.7 allows remote attackers to cause a denial of service via a multipart/form-data encoded form with a parameter name that references the public getMultipartRequestHandler method, which provides further access to elements in the CommonsMultipartRequestHandler implementation and BeanUtils.
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Analysis
by VulDB Data Team • 04/22/2026
The vulnerability described in CVE-2006-1547 represents a critical denial of service weakness within the Apache Struts framework that existed prior to version 1.2.9. This flaw specifically affects the ActionForm component when used in conjunction with BeanUtils version 1.7, creating a pathway for remote attackers to disrupt system availability through carefully crafted multipart form data submissions. The vulnerability exploits a fundamental design oversight in how parameter names are processed within the Struts framework, particularly when handling multipart requests that contain specially constructed parameter references.
The technical mechanism behind this vulnerability involves the manipulation of parameter names in multipart/form-data encoded forms to reference the public getMultipartRequestHandler method. When the Struts framework processes these malformed requests, it inadvertently exposes internal implementation details of the CommonsMultipartRequestHandler class through the BeanUtils component. This exposure occurs because the framework fails to properly validate or sanitize parameter names that could potentially trigger method resolution through reflection mechanisms. The flaw essentially allows attackers to traverse the internal structure of the multipart request handling system, potentially accessing sensitive implementation details that should remain hidden from external input processing.
From an operational perspective, this vulnerability enables remote attackers to cause significant disruption to web applications built on the Struts framework by consuming excessive system resources or triggering unexpected behavior in the request processing pipeline. The denial of service impact can range from partial service degradation to complete application unavailability, depending on how the system handles the malformed requests. The vulnerability is particularly dangerous because it requires no authentication or specialized privileges to exploit, making it a prime target for automated attack tools that scan for vulnerable systems. Organizations running Struts applications without the appropriate patches are exposed to potential disruption of their web services, which could have cascading effects on business operations and user access.
The underlying security weakness aligns with CWE-20, which describes improper input validation, and demonstrates how insufficient sanitization of user-supplied data can lead to unintended code execution paths or resource exhaustion. This vulnerability also relates to ATT&CK technique T1499.004, which covers network denial of service attacks through resource exhaustion. The flaw represents a classic example of how framework-level components can create attack surfaces when they fail to properly isolate external input from internal system operations, particularly in the context of reflection-based method resolution. Organizations should implement immediate patches to Struts 1.2.9 or later versions, while also considering additional input validation measures to prevent similar issues in other frameworks and applications that may be susceptible to similar parameter manipulation techniques.