CVE-2015-4301 in NX-OS
Summary
by MITRE
Cisco NX-OS on Nexus 9000 devices 11.1(1c) allows remote authenticated users to cause a denial of service (device hang) via large files that are copied to a device's filesystem, aka Bug ID CSCuu77225.
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Analysis
by VulDB Data Team • 06/12/2022
The vulnerability identified as CVE-2015-4301 affects Cisco NX-OS software running on Nexus 9000 series network devices with version 11.1(1c) and potentially other affected releases. This security flaw represents a significant denial of service weakness that can be exploited by remote authenticated attackers to disrupt network operations. The vulnerability specifically manifests when large files are copied to the device's filesystem, causing the system to become unresponsive or hang, effectively rendering the network infrastructure unavailable to legitimate users. The issue stems from inadequate input validation and resource handling within the file system processing mechanisms of the NX-OS operating system.
The technical implementation of this vulnerability involves the improper handling of large file operations within the device's file system management subsystem. When authenticated users attempt to copy substantial files to the device's storage, the system fails to properly manage memory allocation and processing resources required for such operations. This results in a condition where the device's processor becomes overwhelmed by the file handling operations, leading to a complete system hang where normal device functions cease. The flaw demonstrates characteristics consistent with CWE-122, which describes improper restriction of operations within the bounds of a memory buffer, and may also relate to CWE-400, representing an unspecified resource management issue that leads to system instability.
The operational impact of CVE-2015-4301 extends beyond simple service disruption to potentially compromise network reliability and business continuity. Network administrators managing Nexus 9000 devices running affected software versions face the risk of unauthorized parties causing intentional outages that could affect critical network infrastructure. The vulnerability is particularly concerning because it requires only authenticated access, meaning that insiders or attackers who have gained legitimate credentials can exploit this weakness. The device hang condition typically requires manual intervention to restore normal operations, including device rebooting, which creates additional service interruption periods. Organizations relying on these network devices for critical infrastructure operations face potential financial losses due to extended downtime and the need for emergency maintenance procedures.
Mitigation strategies for this vulnerability should focus on both immediate remediation and long-term security hardening measures. The most effective immediate solution involves upgrading the affected NX-OS software to a patched version that addresses the file system handling flaw, typically provided through Cisco's security advisory process. Network administrators should implement strict access controls and monitoring to detect unauthorized file transfer activities that could trigger the vulnerability. The implementation of network segmentation and least privilege access models can reduce the attack surface by limiting which users can perform file operations on network devices. Additionally, organizations should establish automated monitoring systems that can detect unusual file transfer patterns or system performance degradation that might indicate exploitation attempts. This vulnerability aligns with ATT&CK technique T1499.004, which covers network denial of service attacks, and demonstrates the importance of proper resource management in network operating systems. Regular security assessments and vulnerability scanning should be conducted to identify similar weaknesses in network infrastructure components and ensure comprehensive protection against both known and emerging threats.