CVE-2018-0245 in Wireless LAN Controller
Summary
by MITRE
A vulnerability in the REST API of Cisco 5500 and 8500 Series Wireless LAN Controller (WLC) Software could allow an unauthenticated, remote attacker to view system information that under normal circumstances should be prohibited. The vulnerability is due to incomplete input and validation checking mechanisms in the REST API URL request. An attacker could exploit this vulnerability by sending a malicious URL to the REST API. If successful, an exploit could allow the attacker to view sensitive system information. Cisco Bug IDs: CSCvg89442.
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Analysis
by VulDB Data Team • 03/08/2023
The vulnerability identified as CVE-2018-0245 affects Cisco 5500 and 8500 Series Wireless LAN Controller software, representing a critical security flaw in the REST API implementation that undermines the fundamental security principles of access control and information protection. This vulnerability stems from insufficient input validation mechanisms within the REST API URL request processing, creating a pathway for unauthorized access to sensitive system information that should remain restricted to authenticated administrators. The flaw exists specifically in the way the system handles URL requests through the REST API interface, where proper validation checks fail to adequately sanitize or verify incoming requests before processing them. The vulnerability allows an unauthenticated remote attacker to exploit the system by crafting malicious URL requests that bypass normal access controls and retrieve confidential data that would typically require proper authentication credentials. This represents a significant deviation from standard security practices where REST APIs should implement robust input validation and authentication mechanisms to prevent unauthorized access to system resources. The Cisco Bug ID CSCvg89442 documents this specific weakness in the software's API handling capabilities, highlighting the incomplete validation mechanisms that enable this particular attack vector.
The technical exploitation of CVE-2018-0245 demonstrates a clear violation of the principle of least privilege, where an attacker can gain unauthorized access to system information without requiring valid credentials or authentication. The incomplete input validation allows attackers to manipulate URL parameters in ways that should be prevented by proper sanitization and validation routines. This vulnerability directly maps to CWE-20, which describes "Improper Input Validation" as a fundamental weakness that enables various attack patterns including information disclosure, privilege escalation, and denial of service. The REST API URL request processing fails to implement proper parameter validation, allowing maliciously crafted requests to traverse the system's normal access control boundaries and retrieve sensitive data. Attackers can leverage this flaw to perform reconnaissance activities by accessing system configurations, user information, network details, and other sensitive data that should remain protected within the wireless controller environment. The remote nature of this vulnerability means that attackers can exploit it from outside the network perimeter, eliminating the need for physical access or internal network presence, which significantly increases the attack surface and potential impact.
The operational impact of this vulnerability extends beyond simple information disclosure, as the exposed system information could provide attackers with critical data needed for further exploitation attempts. An attacker who successfully exploits this vulnerability gains access to sensitive system information that could include network configurations, user credentials, device settings, and other confidential data that would normally be restricted to authorized personnel. This information disclosure could enable more sophisticated attacks such as privilege escalation, lateral movement within the network, or targeted attacks against other systems that rely on the exposed data. The vulnerability's remote exploitability makes it particularly dangerous as it allows attackers to conduct reconnaissance without detection, potentially enabling extended periods of unauthorized access before the compromise is discovered. Organizations using affected Cisco WLC devices face significant risk of unauthorized access to their wireless network infrastructure, which could lead to complete network compromise and data breaches. The impact is especially severe in enterprise environments where wireless controllers manage critical network access and security policies, as this vulnerability effectively undermines the security controls that protect these essential network components.
Mitigation strategies for CVE-2018-0245 should prioritize immediate implementation of network segmentation and access controls to limit exposure of affected devices to untrusted networks. Organizations should implement firewall rules and access control lists that restrict direct access to the REST API endpoints on affected WLC devices, particularly from external networks where the vulnerability can be exploited. Cisco has released patches and software updates to address this vulnerability, and organizations must apply these updates as soon as possible to remediate the flawed input validation mechanisms. Network administrators should also implement monitoring and logging of REST API access attempts to detect potential exploitation attempts and establish baseline behavior for normal system operations. The vulnerability highlights the importance of implementing proper input validation and parameter sanitization in all API endpoints, which aligns with ATT&CK technique T1213.002 for Credential Access - Credentials in Files, where attackers may exploit weak input validation to extract sensitive information from system resources. Additionally, organizations should conduct comprehensive security assessments of their wireless infrastructure to identify other potential vulnerabilities in similar API implementations and ensure that all network devices properly implement authentication and authorization controls. The remediation process should include verification that the applied patches have correctly addressed the input validation flaws and that no residual vulnerabilities remain in the system's API handling mechanisms.