CVE-2014-0718 in IPS
Summary
by MITRE
The produce-verbose-alert feature in Cisco IPS Software 7.1 before 7.1(8)E4 and 7.2 before 7.2(2)E4 allows remote attackers to cause a denial of service (Analysis Engine process outage) via fragmented packets, aka Bug ID CSCui91266.
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Analysis
by VulDB Data Team • 06/09/2021
The vulnerability described in CVE-2014-0718 represents a significant denial of service weakness within Cisco's Intrusion Prevention System software ecosystem. This flaw specifically affects the produce-verbose-alert functionality in Cisco IPS Software versions 7.1 prior to 7.1(8)E4 and 7.2 prior to 7.2(2)E4, creating a critical operational risk for network security infrastructure. The vulnerability manifests when the system processes fragmented packets, leading to an Analysis Engine process outage that effectively disables the intrusion prevention capabilities of affected devices. This issue falls under the category of CWE-129 Input Validation, where inadequate validation of packet fragmentation patterns leads to system instability.
The technical exploitation of this vulnerability occurs through carefully crafted fragmented network packets that trigger a specific code path within the Analysis Engine component of Cisco IPS. When the system encounters these malformed fragmented packets, the verbose alert generation mechanism fails to properly handle the fragmentation state, causing the Analysis Engine process to crash or become unresponsive. This process outage directly impacts the device's ability to perform intrusion detection and prevention functions, leaving network traffic unprotected against potential threats. The vulnerability demonstrates a classic buffer overflow or memory corruption pattern where the system's handling of fragmented packet data exceeds allocated memory boundaries or fails to properly manage state transitions during packet reassembly.
The operational impact of this vulnerability extends beyond simple service disruption to represent a comprehensive security risk for organizations relying on Cisco IPS solutions. Network administrators face the potential for complete loss of intrusion prevention capabilities across affected systems, creating windows of vulnerability where malicious traffic can pass undetected through the network infrastructure. The remote nature of the attack means that adversaries can exploit this weakness from outside the network perimeter without requiring physical access or elevated privileges. This vulnerability directly maps to ATT&CK technique T1499.004 Network Denial of Service, where attackers target network infrastructure to disrupt services. Organizations may experience cascading failures as the Analysis Engine process outage propagates through the system, potentially affecting other security services that depend on the IPS functionality.
Mitigation strategies for this vulnerability require immediate implementation of Cisco's security advisories and software updates to patch the affected versions. Network administrators should prioritize updating to the patched versions 7.1(8)E4 and 7.2(2)E4, which contain fixes for the fragmented packet handling logic. Additionally, implementing temporary network segmentation or disabling verbose alert generation can provide interim protection while full patches are deployed. The vulnerability highlights the importance of proper input validation and robust error handling in security appliances, particularly those handling network traffic. Organizations should also consider implementing network monitoring solutions to detect unusual patterns of packet fragmentation that may indicate exploitation attempts, as well as maintaining comprehensive backup and recovery procedures for critical network security infrastructure.