CVE-2004-2095 in Honeyd
Summary
by MITRE
Honeyd before 0.8 replies to TCP packets with the SYN and RST flags set, which allows remote attackers to identify IP addresses that are being simulated by Honeyd.
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Analysis
by VulDB Data Team • 06/25/2018
The vulnerability identified as CVE-2004-2095 affects honeyd versions prior to 0.8, representing a significant flaw in network simulation and deception systems. This issue resides within the TCP packet handling mechanism of honeyd, a network honeypot and network simulation tool designed to mimic network services and hosts for security research and threat detection purposes. The vulnerability specifically manifests in how honeyd processes incoming TCP packets, creating an unintended behavior that exposes the underlying network infrastructure to potential reconnaissance attacks.
The technical flaw occurs when honeyd receives TCP packets and responds with both the SYN and RST flags simultaneously set in its response packets. This particular combination of flags violates standard TCP protocol behavior where SYN and RST flags are mutually exclusive in normal network communication. The implementation error causes honeyd to send malformed responses that inadvertently reveal information about the network topology and host configuration to remote attackers who are monitoring network traffic. This behavior creates a fingerprinting opportunity that allows adversaries to distinguish between real network hosts and those being simulated by honeyd.
The operational impact of this vulnerability extends beyond simple information disclosure, as it fundamentally undermines the security premise of network simulation tools. Attackers can leverage this flaw to perform network mapping and reconnaissance activities by sending TCP packets to various IP addresses and observing the honeyd responses. When an attacker sends a TCP packet to an IP address being simulated by honeyd, they receive a response with both SYN and RST flags set, which indicates to the attacker that the address is being simulated rather than representing a real host. This capability directly compromises the stealth and effectiveness of honeyd deployments, as it reveals the presence and configuration of simulation infrastructure to potential adversaries.
The vulnerability aligns with CWE-119, which addresses improper access to critical sections of memory, and relates to the broader category of protocol implementation flaws that can be exploited for reconnaissance purposes. From an ATT&CK framework perspective, this vulnerability maps to techniques involving network sniffing and reconnaissance activities, specifically T1046 for network service scanning and T1592 for reconnaissance using network discovery tools. The flaw represents a critical design oversight that allows attackers to bypass the intended deception mechanisms of honeyd, potentially leading to more sophisticated attacks against the underlying network infrastructure. Organizations relying on honeyd for network security research and monitoring must understand that this vulnerability creates a direct pathway for adversaries to identify and potentially target the simulated hosts within their network environments.
Mitigation strategies for CVE-2004-2095 require immediate patching of honeyd installations to version 0.8 or later, where the TCP response handling has been corrected to properly implement TCP protocol semantics. Network administrators should also implement additional monitoring and logging mechanisms to detect anomalous TCP packet behavior that might indicate exploitation attempts. The vulnerability demonstrates the critical importance of proper protocol implementation in security tools and highlights the need for comprehensive testing of network simulation software to prevent information disclosure vulnerabilities that could compromise entire network defense strategies.