CVE-2019-1830 in Wireless LAN Controller
Summary
by MITRE
A vulnerability in Locally Significant Certificate (LSC) management for the Cisco Wireless LAN Controller (WLC) could allow an authenticated, remote attacker to cause the device to unexpectedly restart, which causes a denial of service (DoS) condition. The attacker would need to have valid administrator credentials. The vulnerability is due to incorrect input validation of the HTTP URL used to establish a connection to the LSC Certificate Authority (CA). An attacker could exploit this vulnerability by authenticating to the targeted device and configuring a LSC certificate. An exploit could allow the attacker to cause a DoS condition due to an unexpected restart of the device.
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Analysis
by VulDB Data Team • 09/04/2023
The vulnerability identified as CVE-2019-1830 resides within the Locally Significant Certificate management functionality of Cisco Wireless LAN Controller devices, representing a critical security flaw that compromises system availability. This weakness specifically affects the processing of HTTP URLs during LSC Certificate Authority connections, creating a pathway for authenticated remote attackers to disrupt service operations. The vulnerability demonstrates the inherent risks associated with insufficient input validation mechanisms in enterprise wireless infrastructure components, particularly when administrative credentials are compromised. The affected WLC devices operate under the assumption that properly authenticated administrators can be trusted, failing to implement adequate validation checks on URL parameters that could lead to system instability.
The technical implementation of this vulnerability stems from inadequate input validation within the HTTP URL processing pipeline used for LSC CA connections. When an authenticated administrator configures LSC certificates through the web interface, the system fails to properly sanitize or validate the HTTP URL provided by the attacker. This validation gap allows maliciously crafted URLs to trigger unexpected behavior in the certificate management subsystem. The flaw manifests as a buffer overflow or memory corruption condition that ultimately results in an uncontrolled system restart, effectively rendering the wireless access point unavailable to legitimate users. This type of vulnerability aligns with CWE-20, which describes improper input validation, and represents a classic example of how seemingly benign configuration parameters can become attack vectors when proper sanitization measures are absent.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise enterprise wireless network availability and business continuity. Organizations relying on Cisco WLC devices for wireless infrastructure management face significant risk when this vulnerability is exploited, as the DoS condition affects not only the targeted device but potentially entire wireless network segments. The requirement for valid administrator credentials limits the attack surface compared to unauthenticated vulnerabilities, yet the potential for service disruption remains severe given the critical nature of wireless infrastructure in modern enterprise environments. Network administrators must consider that this vulnerability could be exploited by insider threats or compromised administrative accounts, making it particularly dangerous in environments where privileged access is not adequately monitored or restricted. The unexpected restart behavior also creates potential for cascading failures in redundant wireless systems where multiple controllers depend on each other for proper operation.
Mitigation strategies for CVE-2019-1830 should focus on both immediate protective measures and long-term architectural improvements. Cisco has released software updates that address the input validation gap in LSC certificate processing, and organizations should prioritize applying these patches to all affected WLC devices. Network segmentation and access control measures should be enhanced to limit administrative access to only necessary personnel, while implementing robust monitoring for suspicious certificate configuration activities. The vulnerability highlights the importance of implementing principle of least privilege controls for administrative interfaces and establishing automated monitoring for configuration changes that could indicate exploitation attempts. Organizations should also consider implementing network-based intrusion detection systems capable of identifying malicious URL patterns used in exploitation attempts, while maintaining detailed audit logs of all administrative activities. This vulnerability demonstrates the necessity of applying security controls not just at the network perimeter but also within critical infrastructure components where administrative functions are processed, aligning with ATT&CK technique T1078 for valid accounts and T1499 for endpoint disruption.