CVE-2012-1317 in IOS
Summary
by MITRE
The multicast implementation in Cisco IOS before 15.1(1)SY allows remote attackers to cause a denial of service (Route Processor crash) by sending packets at a high rate, aka Bug ID CSCts37717.
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Analysis
by VulDB Data Team • 05/11/2026
The vulnerability described in CVE-2012-1317 represents a critical denial of service weakness within Cisco IOS multicast functionality that affected versions prior to 15.1(1)SY. This issue manifests when remote attackers exploit the multicast implementation to flood the system with packets at an excessive rate, leading to a complete route processor crash that renders the affected device non-operational. The vulnerability specifically targets the multicast routing protocols and forwarding mechanisms that are fundamental to network communication in enterprise and service provider environments where multicast traffic is commonly utilized for applications such as video streaming, voice over IP, and real-time data distribution. The bug ID CSCts37717 identifies this as a specific software flaw within Cisco's routing implementation that was discovered and documented by the vendor's security team.
The technical root cause of this vulnerability stems from inadequate input validation and resource management within the multicast packet processing code of Cisco IOS. When the system receives multicast packets at rates exceeding normal operational thresholds, the route processor becomes overwhelmed with processing demands that exceed the allocated memory and processing capacity. This condition leads to a buffer overflow or memory corruption scenario where the routing processor's stability is compromised, ultimately causing a system crash that requires manual intervention and reboot to restore normal operations. The flaw operates at the network layer and affects the core routing engine that manages multicast group memberships and forwarding decisions, making it particularly dangerous in production environments where continuous network availability is critical. The vulnerability does not permit arbitrary code execution or privilege escalation but creates a significant availability risk that can be exploited to disrupt network services.
The operational impact of CVE-2012-1317 extends beyond simple service disruption to encompass potential business continuity issues and network reliability concerns. Organizations utilizing affected Cisco IOS versions may experience complete network outages when attackers leverage this vulnerability, particularly in environments where multicast traffic is prevalent such as campus networks, service provider core routers, or data center infrastructures. The attack vector requires only network connectivity to the vulnerable device, making it accessible to remote threat actors without requiring physical access or elevated privileges. This vulnerability aligns with CWE-129, which addresses issues related to input validation and improper handling of input data that can lead to memory corruption, and represents a classic example of a resource exhaustion attack pattern. The attack can be executed using readily available network tools to generate sustained packet flows that overwhelm the multicast processing capabilities of the device.
Mitigation strategies for this vulnerability primarily involve applying the appropriate Cisco IOS software updates and patches that address the multicast implementation flaws. Organizations should prioritize upgrading their Cisco IOS versions to 15.1(1)SY or later releases that contain the necessary fixes for this vulnerability. Network administrators should also implement rate limiting and access control measures to restrict multicast packet flows and reduce the attack surface. The implementation of monitoring systems that can detect unusual multicast traffic patterns may help identify exploitation attempts before they cause complete system failures. Additionally, organizations should consider implementing redundant network paths and failover mechanisms to minimize the impact of potential attacks on critical network infrastructure. This vulnerability demonstrates the importance of maintaining current security patches and the potential consequences of running outdated network operating systems in enterprise environments where network availability is paramount. The remediation process should include thorough testing of updated firmware in non-production environments before deployment to ensure compatibility with existing network configurations and services.