CVE-2003-0647 in IOS
Summary
by MITRE
Buffer overflow in the HTTP server for Cisco IOS 12.2 and earlier allows remote attackers to execute arbitrary code via an extremely long (2GB) HTTP GET request.
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Analysis
by VulDB Data Team • 07/15/2024
The vulnerability described in CVE-2003-0647 represents a critical buffer overflow flaw within Cisco IOS software versions 12.2 and earlier, specifically affecting the embedded HTTP server component. This issue arises from inadequate input validation mechanisms that fail to properly handle excessively long HTTP GET requests, creating a condition where memory allocation becomes compromised. The flaw manifests when an attacker submits a malformed HTTP GET request containing an extremely long URL or parameter string approaching 2 gigabytes in size, which exceeds the buffer capacity allocated for processing such requests within the IOS operating system.
The technical implementation of this vulnerability stems from improper bounds checking within the HTTP server module of Cisco IOS, which does not adequately validate the length of incoming HTTP GET requests before attempting to process them. When the system encounters a request exceeding the predetermined buffer size, it overflows into adjacent memory regions, potentially allowing an attacker to overwrite critical system data structures, function return addresses, or executable code segments. This type of buffer overflow vulnerability aligns with CWE-121, which categorizes stack-based buffer overflow conditions where insufficient bounds checking allows attackers to overwrite adjacent memory locations. The vulnerability is particularly concerning because it operates at the network protocol level, enabling remote exploitation without requiring physical access or authentication credentials.
The operational impact of CVE-2003-0647 extends beyond simple denial-of-service scenarios, as it provides attackers with the capability to execute arbitrary code on affected Cisco devices. This remote code execution vulnerability can be leveraged to gain complete control over the network infrastructure, potentially enabling attackers to install backdoors, modify network configurations, redirect traffic, or establish persistent access points within the network environment. The attack vector is particularly dangerous because it requires no specialized authentication or local access, making it a prime target for automated exploitation campaigns. According to ATT&CK framework, this vulnerability maps to T1059.007 for command and scripting interpreter and T1021.001 for remote services, as it enables unauthorized remote access to network devices through compromised HTTP services.
Mitigation strategies for this vulnerability require immediate implementation of Cisco IOS patches and firmware updates addressing the buffer overflow condition in the HTTP server module. Network administrators should disable the HTTP server functionality entirely on affected devices when it is not strictly required for operations, as this eliminates the attack surface associated with the vulnerable component. Additionally, implementing network access controls through firewalls and access control lists can help restrict access to HTTP server ports, while monitoring systems should be configured to detect anomalous HTTP GET request patterns that may indicate exploitation attempts. The vulnerability also highlights the importance of regular security assessments and vulnerability management processes, as it demonstrates how legacy software components can harbor critical security flaws that remain undetected for extended periods. Organizations should consider implementing network segmentation strategies to limit the potential impact of successful exploitation and establish incident response procedures specifically addressing remote code execution vulnerabilities in network infrastructure devices.