CVE-2006-0752 in Honeyd
Summary
by MITRE
Niels Provos Honeyd before 1.5 replies to certain illegal IP packet fragments that other IP stack implementations would drop, which allows remote attackers to identify IP addresses that are being simulated using honeyd.
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Analysis
by VulDB Data Team • 07/19/2018
The vulnerability identified as CVE-2006-0752 resides within the Niels Provos Honeyd network simulation tool, specifically affecting versions prior to 1.5. This flaw represents a significant security issue that undermines the core purpose of network simulation by exposing the underlying network topology. Honeyd is designed to create network simulation environments that can mimic various network services and operating systems to detect and analyze network activity, but this vulnerability compromises that fundamental security model.
The technical flaw manifests in Honeyd's handling of IP packet fragments that violate standard network protocols. When Honeyd encounters certain illegal IP packet fragments, it responds in a manner that differs from typical IP stack implementations, which would normally drop such malformed packets. This inconsistent behavior creates a unique response pattern that remote attackers can exploit to determine which IP addresses within a network are being simulated by Honeyd. The vulnerability stems from the software's failure to properly validate incoming packet fragments against established network protocol standards.
The operational impact of this vulnerability extends beyond simple information disclosure, as it directly compromises the effectiveness of network security testing and simulation environments. Attackers can leverage this weakness to map network topology and identify which systems are running simulated network services, effectively undermining the security testing process that organizations rely on to identify vulnerabilities. This information disclosure can be particularly damaging in penetration testing environments where the goal is to maintain operational security and prevent adversaries from understanding the true network structure.
This vulnerability aligns with CWE-1175, which addresses improper handling of IP fragments in network applications, and demonstrates the broader category of protocol implementation flaws that can create security weaknesses. The attack vector follows patterns consistent with reconnaissance techniques found in the MITRE ATT&CK framework under the reconnaissance phase, specifically targeting network discovery and enumeration capabilities. Organizations utilizing Honeyd for security testing must recognize that this vulnerability creates a backdoor that adversaries can use to bypass the very security controls that the tool is meant to establish.
The mitigation strategy requires immediate upgrading to Honeyd version 1.5 or later, where the developers have addressed the fragment handling behavior to align with standard IP stack implementations. Additionally, network administrators should implement proper access controls and monitoring to detect unusual packet fragment patterns that might indicate exploitation attempts. The vulnerability highlights the importance of maintaining up-to-date network security tools and demonstrates how seemingly minor protocol implementation differences can create significant security risks in network simulation environments.