CVE-2014-3268 in IOS
Summary
by MITRE
Cisco IOS 15.2(4)M4 on Cisco Unified Border Element (CUBE) devices allows remote attackers to cause a denial of service (input-queue consumption and traffic-processing outage) via crafted RTCP packets, aka Bug ID CSCuj72215.
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Analysis
by VulDB Data Team • 06/20/2021
Cisco IOS version 15.2(4)M4 running on Cisco Unified Border Element devices contains a critical vulnerability that enables remote attackers to trigger a denial of service condition through manipulation of Real-time Transport Control Protocol packets. This vulnerability specifically affects the input queue handling mechanism within the router's traffic processing pipeline, creating a condition where legitimate network traffic becomes disrupted due to excessive resource consumption in the packet processing queues.
The technical flaw resides in the improper handling of malformed RTCP packets that are processed by the CUBE's media gateway controller functionality. When these crafted packets are received, they cause the input queue to consume excessive memory resources and processing cycles, leading to a cascading failure where normal traffic processing becomes impaired. The vulnerability stems from insufficient validation of packet headers and payload structures within the RTCP processing module, allowing attackers to exploit the lack of proper bounds checking and input sanitization mechanisms. This weakness aligns with CWE-129 Input Validation and CWE-772 Missing Release of Resource and CWE-674 Uncontrolled Resource Consumption, as the system fails to properly validate incoming data and manage resource allocation during packet processing operations.
The operational impact of this vulnerability is severe as it can result in complete traffic processing outages for the affected CUBE devices, disrupting voice and video communications across the network infrastructure. Attackers can maintain persistent denial of service conditions by continuously sending malformed RTCP packets, causing sustained input queue exhaustion that prevents legitimate media traffic from being processed. The disruption affects not only the immediate device but can cascade through the network topology as the CUBE acts as a critical border element for media traffic routing. This vulnerability particularly impacts enterprise and service provider networks where CUBE devices serve as gateways for VoIP and multimedia services, potentially affecting thousands of concurrent users and business-critical communication channels.
Mitigation strategies should include immediate implementation of access control lists to filter RTCP traffic at network boundaries, applying the latest Cisco IOS patches that address the specific input queue handling flaw, and configuring rate limiting mechanisms to prevent excessive packet processing. Network administrators should also implement monitoring solutions to detect anomalous RTCP packet patterns and establish automated alerting for input queue utilization thresholds. The recommended approach aligns with ATT&CK technique T1498 Network Denial of Service which emphasizes the importance of protecting network infrastructure from resource exhaustion attacks. Additionally, organizations should consider implementing network segmentation to isolate CUBE devices and reduce the attack surface, while maintaining regular vulnerability assessments to identify similar input validation weaknesses in other network components. The patching process should be prioritized as a critical security measure, with careful testing to ensure compatibility with existing network configurations and services.