CVE-2005-0068 in TCP
Summary
by MITRE
The original design of ICMP does not require authentication for host-generated ICMP error messages, which makes it easier for attackers to forge ICMP error messages for specific TCP connections and cause a denial of service, as demonstrated using (1) blind connection-reset attacks with forged "Destination Unreachable" messages, (2) blind throughput-reduction attacks with forged "Source Quench" messages, or (3) blind throughput-reduction attacks with forged ICMP messages that cause the Path MTU to be reduced. NOTE: CVE-2004-0790, CVE-2004-0791, and CVE-2004-1060 have been SPLIT based on different attacks; CVE-2005-0065, CVE-2005-0066, CVE-2005-0067, and CVE-2005-0068 are related identifiers that are SPLIT based on the underlying vulnerability. While CVE normally SPLITs based on vulnerability, the attack-based identifiers exist due to the variety and number of affected implementations and solutions that address the attacks instead of the underlying vulnerabilities.
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Analysis
by VulDB Data Team • 06/30/2021
The vulnerability described in CVE-2005-0068 stems from a fundamental design flaw in the Internet Control Message Protocol version 2 icmp implementation that lacks proper authentication mechanisms for host-generated error messages. This weakness exists within the core internet protocol suite and affects the fundamental security model of icmp communications. The protocol was originally designed with simplicity and reliability as primary concerns rather than security, leaving critical gaps that attackers can exploit to manipulate network traffic. This design oversight creates a significant attack surface that impacts network availability and integrity across various implementations.
The technical flaw manifests when attackers can forge icmp error messages without authentication requirements, specifically targeting tcp connections through three primary attack vectors. The first vector involves blind connection-reset attacks using forged "destination unreachable" messages that can terminate legitimate tcp sessions without proper verification. The second approach utilizes forged "source quench" messages to perform blind throughput-reduction attacks that degrade network performance. The third method involves crafting specific icmp messages that manipulate the path mtu (maximum transmission unit) to reduce network throughput. These attacks exploit the absence of cryptographic authentication or message integrity checks in the icmp protocol design.
The operational impact of this vulnerability extends beyond simple denial of service conditions to potentially compromise network availability and performance across affected systems. When attackers successfully forge these messages, they can cause legitimate tcp connections to be terminated abruptly, leading to service disruption for end users. The throughput reduction attacks can significantly impact network performance, particularly in environments where bandwidth utilization is already constrained. The path mtu reduction attacks can cause fragmentation issues that further degrade network performance and potentially lead to complete communication failures. Organizations with extensive tcp-based network communications face the highest risk from these attacks.
Mitigation strategies for this vulnerability require implementing network-level protections and protocol enhancements to address the underlying authentication deficiencies. Network administrators should deploy icmp filtering rules to limit the propagation of malicious icmp messages and implement proper access controls on network devices. The use of tcp timestamp options and other tcp security mechanisms can help detect and prevent some of these attacks by providing additional verification mechanisms. Network segmentation and monitoring solutions can help identify suspicious icmp traffic patterns that may indicate exploitation attempts. Additionally, implementing proper network access controls and regularly updating network infrastructure can reduce the attack surface. This vulnerability highlights the importance of considering security in protocol design and demonstrates the need for continuous protocol evolution to address emerging threats.
This vulnerability relates to multiple related identifiers including CVE-2005-0065, CVE-2005-0066, CVE-2005-0067, and CVE-2004-0790, CVE-2004-0791, CVE-2004-1060, which represent different attack vectors and implementations. The split classification reflects the complexity of addressing this fundamental protocol weakness rather than focusing on a single technical flaw. This categorization aligns with the common practice of splitting vulnerabilities based on attack methods rather than underlying technical issues when the attack surface varies significantly across implementations. The attack patterns described fall under the attack technique category of denial of service and network disruption, which maps to the attack pattern taxonomy in the attack tree framework. The vulnerability also corresponds to CWE-200, which addresses information exposure through improper error handling in network protocols, and CWE-310, which covers cryptographic weaknesses in network communications. Organizations should consider implementing comprehensive network security monitoring solutions to detect and prevent exploitation attempts, as well as regularly reviewing and updating their network security policies to address protocol-level weaknesses.