CVE-2018-0271 in DNA Center
Summary
by MITRE
A vulnerability in the API gateway of the Cisco Digital Network Architecture (DNA) Center could allow an unauthenticated, remote attacker to bypass authentication and access critical services. The vulnerability is due to a failure to normalize URLs prior to servicing requests. An attacker could exploit this vulnerability by submitting a crafted URL designed to exploit the issue. A successful exploit could allow the attacker to gain unauthenticated access to critical services, resulting in elevated privileges in DNA Center. This vulnerability affects Cisco DNA Center Software Releases prior to 1.1.2. Cisco Bug IDs: CSCvi09394.
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Analysis
by VulDB Data Team • 02/06/2020
The vulnerability identified as CVE-2018-0271 resides within the API gateway of Cisco Digital Network Architecture DNA Center, representing a critical authentication bypass flaw that fundamentally undermines the security posture of the platform. This weakness stems from inadequate input validation mechanisms that fail to properly normalize Uniform Resource Locators before processing incoming requests, creating a pathway for malicious actors to circumvent established security controls. The vulnerability specifically impacts Cisco DNA Center software versions prior to 1.1.2, leaving numerous deployments exposed to potential exploitation. The issue manifests as a failure in the URL normalization process which allows attackers to craft specially designed requests that can traverse the intended access controls and gain unauthorized access to critical system services.
The technical exploitation of this vulnerability leverages the absence of proper URL sanitization within the API gateway component, enabling attackers to manipulate request paths and bypass authentication mechanisms entirely. This flaw operates at the application layer and can be executed remotely without requiring any valid credentials or prior access to the system. The attacker crafts a malicious URL that exploits the normalization failure, allowing the system to interpret the crafted request in an unintended manner that grants access to protected administrative functions. This type of vulnerability aligns with CWE-174, which addresses the weakness of insufficient input sanitization and normalization, particularly in web application contexts where URL handling is critical for security enforcement. The attack vector operates through standard network protocols and requires only basic network connectivity to the target system, making it particularly dangerous for environments where the DNA Center is exposed to untrusted networks.
The operational impact of this vulnerability extends far beyond simple unauthorized access, as successful exploitation results in elevated privileges within the DNA Center environment, potentially enabling complete system compromise. Attackers who successfully exploit this vulnerability can gain access to critical network management functions, configuration data, and administrative controls that should be restricted to authorized personnel only. This represents a significant escalation from a simple authentication bypass to a full administrative compromise, as the attacker can manipulate network policies, access sensitive configuration information, and potentially disrupt network operations. The vulnerability affects the core functionality of the DNA Center platform, which serves as a central management point for network infrastructure, making it a prime target for adversaries seeking to establish persistent access or cause widespread disruption. The impact is particularly severe given that DNA Center is designed to manage enterprise network infrastructure, where unauthorized access could lead to significant business disruption and potential data breaches.
Mitigation strategies for CVE-2018-0271 center on immediate software updates to version 1.1.2 or later, which contain the necessary patches to address the URL normalization flaw. Organizations should prioritize patching their DNA Center deployments and verify that the update has been properly applied across all instances. Network segmentation and access control measures can provide additional defense-in-depth, limiting the exposure of the DNA Center to untrusted networks and reducing the attack surface. Implementing proper network monitoring and intrusion detection systems can help identify anomalous access patterns that may indicate exploitation attempts. Security teams should also conduct thorough vulnerability assessments to identify any other systems that might be affected by similar URL normalization issues. The remediation process should include validating that the patch has been applied correctly and that no residual vulnerabilities remain in the system configuration. Organizations should also review their access control policies and implement principle of least privilege to minimize the potential impact if any systems remain unpatched or if additional vulnerabilities are discovered. The vulnerability demonstrates the critical importance of proper input validation and normalization in web applications, aligning with ATT&CK technique T1078 for valid accounts and T1566 for phishing attacks that may leverage such authentication bypasses to gain unauthorized access to enterprise network management systems.