CVE-2010-2827 in IOS
Summary
by MITRE
Cisco IOS 15.1(2)T allows remote attackers to cause a denial of service (resource consumption and TCP outage) via spoofed TCP packets, related to embryonic TCP connections that remain in the SYN_RCVD or SYN_SENT state, aka Bug ID CSCti18193.
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Analysis
by VulDB Data Team • 01/21/2025
Cisco IOS version 15.1(2)T contains a critical vulnerability that enables remote attackers to execute denial of service attacks by manipulating embryonic TCP connections. This vulnerability specifically targets the handling of TCP connections in the SYN_RCVD or SYN_SENT states, where connections remain in a transitional phase before establishing a full TCP session. The flaw allows attackers to send spoofed TCP packets that exploit the operating system's connection state management mechanisms, leading to resource exhaustion and subsequent TCP service outages. The vulnerability is categorized under CWE-119 as a memory management issue that affects the proper handling of connection states. The attack vector involves sending malformed TCP packets that cause the system to maintain excessive connection tracking entries in memory, ultimately consuming available resources and rendering the device unable to process legitimate TCP connections. This issue represents a significant operational impact as it can disrupt network services and create availability problems for critical infrastructure. The vulnerability directly maps to ATT&CK technique T1499.004 which involves network denial of service attacks targeting system resources. The root cause stems from inadequate validation of TCP packet sequences and insufficient limits on the number of embryonic connections that can be maintained simultaneously. Attackers can leverage this weakness to flood the system with spoofed connections, causing memory exhaustion and forcing the device to restart or become unresponsive. The impact extends beyond simple service disruption as it can affect network availability for legitimate users and potentially create cascading failures in network infrastructure. Organizations running affected Cisco IOS versions should implement immediate mitigations including connection rate limiting, TCP SYN cookies, and firewall rules to filter suspicious TCP packets. Network administrators should also monitor for unusual connection patterns and implement proper logging to detect exploitation attempts. The vulnerability demonstrates the importance of proper state management in network operating systems and highlights the need for robust connection tracking mechanisms that can handle malformed traffic without exhausting system resources. This weakness in TCP connection handling represents a fundamental security gap that affects the reliability and availability of network services. The exploitability of this vulnerability underscores the critical need for network security professionals to understand TCP protocol behavior and implement appropriate defenses against connection-based attacks. Proper configuration of TCP parameters and implementation of connection tracking limits can significantly reduce the risk of exploitation. The vulnerability also emphasizes the importance of regular security updates and the need for organizations to maintain current knowledge of known vulnerabilities in their network infrastructure components.