CVE-2018-0301 in NX-OS
Summary
by MITRE
A vulnerability in the NX-API feature of Cisco NX-OS Software could allow an unauthenticated, remote attacker to craft a packet to the management interface on an affected system, causing a buffer overflow. The vulnerability is due to incorrect input validation in the authentication module of the NX-API subsystem. An attacker could exploit this vulnerability by sending a crafted HTTP or HTTPS packet to the management interface of an affected system with the NX-API feature enabled. An exploit could allow the attacker to execute arbitrary code as root. Note: NX-API is disabled by default. This vulnerability affects: MDS 9000 Series Multilayer Switches, Nexus 2000 Series Fabric Extenders, Nexus 3000 Series Switches, Nexus 3500 Platform Switches, Nexus 5500 Platform Switches, Nexus 5600 Platform Switches, Nexus 6000 Series Switches, Nexus 7000 Series Switches, Nexus 7700 Series Switches, Nexus 9000 Series Switches in standalone NX-OS mode, Nexus 9500 R-Series Line Cards and Fabric Modules. Cisco Bug IDs: CSCvd45804, CSCve02322, CSCve02412.
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Analysis
by VulDB Data Team • 03/28/2023
The vulnerability described in CVE-2018-0301 represents a critical buffer overflow flaw within the NX-API feature of Cisco NX-OS software that exposes multiple series of enterprise networking equipment to remote code execution risks. This vulnerability specifically targets the authentication module within the NX-API subsystem, where insufficient input validation creates a pathway for malicious actors to craft specially designed packets that can trigger memory corruption. The affected devices include a broad range of Cisco networking hardware spanning from MDS 9000 Series Multilayer Switches to Nexus 9000 Series Switches operating in standalone NX-OS mode, making this a widespread concern across enterprise network infrastructures. The vulnerability's exploitation requires sending crafted HTTP or HTTPS packets to the management interface of affected systems, leveraging the NX-API feature that remains disabled by default but can be enabled through administrative configuration.
The technical implementation of this vulnerability stems from improper input validation mechanisms within the NX-API authentication module, which fails to adequately sanitize or verify incoming packet data before processing. This weakness creates a classic buffer overflow condition where attacker-controlled data exceeds the allocated memory buffer space, potentially allowing arbitrary code execution with root privileges. The attack vector is particularly concerning because it requires no authentication credentials, making it accessible to remote attackers who can exploit the vulnerability from outside the network perimeter. The exploitation process involves crafting malicious packets that specifically target the vulnerable authentication module, bypassing normal security controls and potentially leading to complete system compromise. According to the Common Weakness Enumeration framework, this vulnerability maps to CWE-121, which describes heap-based buffer overflow conditions, and CWE-122, which covers stack-based buffer overflow scenarios, both of which are directly applicable to the memory corruption mechanisms at play.
The operational impact of CVE-2018-0301 extends beyond simple system compromise to encompass complete network infrastructure takeover capabilities. When successfully exploited, the vulnerability allows attackers to execute arbitrary code as root, effectively granting them full administrative control over affected switches. This level of access enables threat actors to modify network configurations, redirect traffic, install backdoors, or establish persistent access points within the network infrastructure. The vulnerability's presence across multiple Cisco product lines creates significant risk for organizations that maintain diverse networking equipment, as a single exploitation attempt could potentially compromise multiple network segments. The default disablement of NX-API provides some protection, but organizations using the feature or those with misconfigured systems remain vulnerable to this attack vector. From an adversary perspective, this vulnerability aligns with ATT&CK technique T1059.007, which covers command and script interpreter usage, and T1068, which involves exploit for privilege escalation, as attackers can leverage the root-level execution capability to maintain persistent access.
Organizations should implement immediate mitigation strategies to address this vulnerability, beginning with disabling the NX-API feature on all affected devices unless absolutely required for operations. Network segmentation and access control measures should be enhanced to limit management interface exposure, particularly when NX-API must remain enabled. Regular security audits should verify that NX-API is disabled by default across all network infrastructure, and administrative procedures should be updated to ensure proper configuration management. Cisco has released patches and software updates to address this vulnerability, and organizations should prioritize applying these updates to all affected systems. Monitoring network traffic for suspicious HTTP or HTTPS packets targeting management interfaces can help detect exploitation attempts, while implementing intrusion detection systems can provide additional layers of protection. The vulnerability also underscores the importance of secure configuration management practices and regular vulnerability assessments to identify and remediate similar weaknesses across network infrastructure components.