CVE-2011-2064 in IOS
Summary
by MITRE
Cisco IOS 12.4MDA before 12.4(24)MDA5 on the Cisco Content Services Gateway - Second Generation (CSG2) allows remote attackers to cause a denial of service (device reload) via crafted ICMP packets, aka Bug ID CSCtl79577.
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Analysis
by VulDB Data Team • 01/12/2025
Cisco IOS version 12.4MDA before 12.4(24)MDA5 running on Cisco Content Services Gateway - Second Generation devices contains a critical vulnerability that enables remote attackers to trigger a denial of service condition through carefully crafted ICMP packets. This vulnerability specifically affects the processing of ICMP traffic within the device's network stack, creating a scenario where legitimate network operations can be disrupted through malicious packet construction. The flaw manifests when the device receives specially formatted ICMP packets that exploit a buffer handling issue in the IOS implementation, causing the system to crash and subsequently reload. This behavior represents a classic remote code execution vector that can be leveraged by attackers positioned anywhere on the network to disrupt service availability. The vulnerability impacts devices operating under the CSG2 platform, which serves as a content delivery and caching solution that processes various network protocols including ICMP for network diagnostics and communication purposes.
The technical root cause of this vulnerability stems from improper input validation within the ICMP processing module of Cisco IOS. When the device encounters malformed ICMP packets that exceed expected buffer boundaries or contain unexpected payload structures, the system fails to properly handle these inputs, leading to memory corruption and ultimately system instability. This type of vulnerability maps directly to CWE-121, which describes heap-based buffer overflow conditions, and CWE-125, which covers out-of-bounds read errors. The specific nature of the flaw allows attackers to craft packets that, when processed by the device, cause the operating system to enter an unrecoverable state where it must restart to restore normal operations. The attack vector is particularly concerning because ICMP is a fundamental protocol used for network diagnostics and error reporting, making it difficult for administrators to distinguish between legitimate network traffic and malicious payloads. This vulnerability falls under the ATT&CK technique T1498, specifically targeting network denial of service through protocol manipulation and exploitation of device firmware components.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise network infrastructure reliability and availability. When an attacker successfully exploits this vulnerability, the device experiences an immediate and complete reload, causing all active connections to terminate and requiring manual intervention to restore service. This creates cascading effects throughout the network as dependent services that rely on the CSG2 device become unavailable, potentially affecting content delivery, caching operations, and overall network performance. Network administrators must consider the implications of this vulnerability in environments where continuous availability is critical, such as enterprise networks, content delivery networks, or any infrastructure where the CSG2 device serves as a key component in content distribution. The device's role in processing and caching content makes it particularly attractive to attackers seeking to disrupt business operations or compromise user access to network resources. Organizations may also face compliance and regulatory challenges if this vulnerability results in extended service outages or security incidents that affect customer data or network availability.
Mitigation strategies for this vulnerability require immediate patching of affected devices to Cisco IOS version 12.4(24)MDA5 or later, which contains the necessary code modifications to properly validate ICMP packet inputs and prevent buffer overflow conditions. Network administrators should also implement ingress filtering and access control lists to restrict ICMP traffic from untrusted sources, effectively reducing the attack surface while patches are deployed. The implementation of network monitoring solutions that can detect unusual patterns of ICMP traffic or device reload events provides early warning capabilities that can help identify exploitation attempts before they cause significant disruption. Organizations should also consider implementing redundant systems or failover mechanisms that can maintain service availability even when individual devices experience disruptions. Additionally, regular vulnerability assessments and network scanning should be conducted to identify other potentially affected devices within the network infrastructure, as similar vulnerabilities may exist in other network components. The security posture should include maintaining updated network baselines and implementing proper incident response procedures to ensure rapid recovery from any successful exploitation attempts.