CVE-2003-1001 in CatOS
Summary
by MITRE
Buffer overflow in the Cisco Firewall Services Module (FWSM) in Cisco Catalyst 6500 and 7600 series devices allows remote attackers to cause a denial of service (crash and reload) via HTTP auth requests for (1) TACACS+ or (2) RADIUS authentication.
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Analysis
by VulDB Data Team • 06/16/2019
The vulnerability identified as CVE-2003-1001 represents a critical buffer overflow flaw within the Cisco Firewall Services Module FWSM operating on Cisco Catalyst 6500 and 7600 series network infrastructure devices. This security weakness specifically manifests when the FWSM processes HTTP authentication requests, creating a pathway for remote attackers to exploit the system through malformed or excessively large input data. The vulnerability affects both TACACS+ and RADIUS authentication mechanisms, which are fundamental components of network access control and user authentication within enterprise environments.
The technical nature of this buffer overflow stems from insufficient input validation and bounds checking within the FWSM's HTTP authentication handling code. When legitimate authentication requests are processed, the system fails to properly validate the length and structure of incoming data, allowing attackers to craft malicious HTTP requests that exceed the allocated buffer space. This condition results in memory corruption that ultimately causes the FWSM process to crash and subsequently reload the entire device, leading to complete service disruption. The vulnerability operates at the application layer and leverages the HTTP protocol as its attack vector, making it particularly dangerous as it can be exploited remotely without requiring physical access or authentication credentials.
The operational impact of CVE-2003-1001 extends beyond simple denial of service, as it can severely compromise network availability and business continuity for organizations relying on Cisco Catalyst series devices. Network administrators face the challenge of maintaining uptime while managing the risk of unauthenticated attackers causing device reloads that can last several minutes, potentially disrupting critical network services and communications. The vulnerability affects organizations with large enterprise networks where these devices serve as primary security gateways, making the potential for cascading failures and extended downtime particularly concerning. This type of vulnerability directly impacts the availability component of the CIA triad and can be categorized under CWE-121 as heap-based buffer overflow, which is classified as a high-risk vulnerability by industry security frameworks.
Mitigation strategies for this vulnerability require immediate implementation of Cisco's recommended security patches and firmware updates, which address the underlying buffer overflow conditions in the FWSM software. Network administrators should also implement access control measures to restrict HTTP authentication requests to trusted sources only, leveraging firewall rules and network segmentation to limit exposure. The vulnerability demonstrates the importance of proper input validation and memory management practices in network security devices, aligning with ATT&CK technique T1499.004 for network denial of service attacks. Organizations should consider implementing network monitoring solutions to detect anomalous HTTP authentication patterns that might indicate exploitation attempts, while also maintaining robust backup and recovery procedures to minimize downtime from potential attacks. This vulnerability serves as a reminder of the critical need for regular security assessments and timely patch management in enterprise network infrastructure environments.