CVE-2004-0710 in Catalyst 6500
Summary
by MITRE
IP Security VPN Services Module (VPNSM) in Cisco Catalyst 6500 Series Switch and the Cisco 7600 Series Internet Routers running IOS before 12.2(17b)SXA, before 12.2(17d)SXB, or before 12.2(14)SY03 could allow remote attackers to cause a denial of service (device crash and reload) via a malformed Internet Key Exchange (IKE) packet.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 07/12/2025
The vulnerability identified as CVE-2004-0710 represents a critical denial of service flaw within the IP Security VPN Services Module of Cisco's enterprise networking infrastructure. This weakness affects the Cisco Catalyst 6500 Series Switch and Cisco 7600 Series Internet Routers running specific versions of IOS software. The vulnerability manifests through improper handling of malformed Internet Key Exchange packets, which are fundamental components in establishing secure VPN connections. The affected IOS versions include releases before 12.2(17b)SXA, 12.2(17d)SXB, and 12.2(14)SY03, indicating a widespread issue across multiple software release trains that were commonly deployed in enterprise and service provider networks. The nature of this vulnerability places it squarely within the realm of network infrastructure security, where device availability is paramount to business continuity and network operations.
The technical flaw lies in the VPNSM module's insufficient input validation mechanisms when processing IKE protocol packets. When a malformed IKE packet is received, the system fails to properly validate the packet structure and content, leading to unpredictable behavior that ultimately results in a device crash and subsequent automatic reload. This occurs because the vulnerable code does not implement adequate bounds checking or packet parsing error handling, allowing malicious actors to craft specially crafted packets that trigger buffer overflows or other memory corruption conditions. The vulnerability operates at the protocol processing layer where IKE messages are parsed and interpreted, making it particularly dangerous as it can be exploited without requiring authentication or privileged access to the network device. From a cybersecurity perspective, this vulnerability demonstrates poor defensive programming practices and highlights the importance of robust input validation in network protocol implementations.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromising entire network infrastructures. When exploited, the vulnerability causes devices to crash and reload automatically, leading to temporary network outages that can affect critical business operations, especially in environments where these routers and switches serve as core network components. The automatic reload process can also result in temporary loss of network connectivity for users and applications relying on VPN services, potentially causing cascading failures throughout the network. Organizations using affected Cisco devices may experience unexpected downtime, increased network management overhead, and potential security implications if attackers leverage this vulnerability for persistent disruption campaigns. The vulnerability's remote exploitability means that attackers can potentially trigger the denial of service from outside the network perimeter, making it particularly concerning for organizations with exposed router interfaces. This weakness aligns with CWE-129, which describes improper input validation, and represents a classic example of how network protocol implementations can fail to handle malformed data gracefully.
Mitigation strategies for this vulnerability primarily focus on immediate software updates and patches provided by Cisco to address the specific IOS version issues. Organizations should prioritize upgrading affected devices to patched IOS versions, specifically those released after the vulnerable release trains mentioned in the CVE description. Network administrators should also implement network segmentation and access control measures to limit exposure of vulnerable devices to untrusted networks. Monitoring network traffic for suspicious IKE packet patterns can help detect potential exploitation attempts, though this approach requires significant network visibility and analysis capabilities. Additionally, implementing redundant network paths and failover mechanisms can help maintain service availability during potential exploitation events, while maintaining detailed logging and alerting systems enables rapid response to any denial of service incidents. The vulnerability underscores the importance of maintaining current security patches and implementing comprehensive network monitoring strategies to detect and respond to exploitation attempts effectively.