CVE-2011-5034 in Geronimo
Summary
by MITRE
Apache Geronimo 2.2.1 and earlier computes hash values for form parameters without restricting the ability to trigger hash collisions predictably, which allows remote attackers to cause a denial of service (CPU consumption) by sending many crafted parameters. NOTE: this might overlap CVE-2011-4461.
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Analysis
by VulDB Data Team • 01/05/2025
Apache Geronimo versions 2.2.1 and earlier contain a critical vulnerability in their parameter handling mechanism that enables remote attackers to perform hash collision attacks. This vulnerability stems from the web application server's insufficient protection against predictable hash collision attacks during form parameter processing. The flaw occurs when the application server computes hash values for form parameters without implementing proper collision resistance measures, allowing malicious actors to craft specifically designed parameters that deliberately trigger hash collisions within the server's internal data structures.
The technical implementation of this vulnerability involves the use of hash tables or similar data structures that are commonly employed for efficient parameter storage and retrieval in web applications. When attackers send multiple crafted parameters that map to the same hash bucket, the hash table's performance degrades significantly from O(1) to O(n) complexity, where n represents the number of colliding elements. This degradation causes the server to consume excessive CPU resources as it processes each collision, effectively creating a denial of service condition. The vulnerability specifically affects the parameter processing logic where form data is parsed and stored in memory structures that rely on hash-based indexing.
The operational impact of CVE-2011-5034 is severe and can result in complete service disruption for affected Apache Geronimo installations. Remote attackers can exploit this vulnerability by sending carefully constructed HTTP requests containing numerous parameters designed to create hash collisions. The attack requires minimal privileges and can be executed from any network location, making it particularly dangerous for publicly accessible web applications. The CPU consumption increase can be exponential, leading to system resource exhaustion and making the application unavailable to legitimate users. This vulnerability directly aligns with CWE-327, which addresses the use of weak cryptographic hash functions, and represents a classic example of a hash collision attack that has been documented in various security contexts.
Organizations affected by this vulnerability should immediately implement mitigations including upgrading to Apache Geronimo version 2.2.2 or later, which contains fixes for this specific issue. Additional protective measures include implementing parameter validation controls that limit the number of parameters accepted in a single request, configuring rate limiting mechanisms to prevent excessive parameter processing, and employing intrusion detection systems that can identify suspicious parameter patterns. The attack vector for this vulnerability is consistent with techniques described in the MITRE ATT&CK framework under the 'Resource Exhaustion' tactic, where adversaries consume system resources to deny service to legitimate users. Network administrators should also consider implementing application firewalls that can detect and block requests containing suspicious parameter combinations that may trigger hash collision scenarios.