CVE-2019-1837 in Unified Communications Manager
Summary
by MITRE
A vulnerability in the User Data Services (UDS) API of Cisco Unified Communications Manager (Unified CM) could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on the management GUI. The vulnerability is due to improper validation of input parameters in the UDS API requests. An attacker could exploit this vulnerability by sending a crafted request to the UDS API of an affected device. A successful exploit could allow the attacker to make the A Cisco DB service quit unexpectedly, preventing admin access to the Unified CM management GUI. Manual intervention may be required to restore normal operation. Software versions 10.5, 11.5, 12.0, 12.5 are affected.
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Analysis
by VulDB Data Team • 09/04/2023
The vulnerability identified as CVE-2019-1837 resides within the User Data Services API of Cisco Unified Communications Manager, a critical component in enterprise voice and collaboration environments. This flaw represents a significant security weakness that could severely impact the availability and operational integrity of unified communication systems. The vulnerability specifically affects Cisco Unified CM versions 10.5, 11.5, 12.0, and 12.5, making it a widespread concern across multiple generations of the platform. The UDS API serves as a crucial interface for managing user data and system configurations, making it a prime target for attackers seeking to disrupt business operations.
The technical root cause of this vulnerability stems from inadequate input validation mechanisms within the UDS API implementation. When processing requests, the system fails to properly validate or sanitize input parameters, creating an entry point for malicious actors to craft specially designed requests that can trigger unexpected behavior. This weakness aligns with CWE-20, which categorizes improper input validation as a fundamental software security flaw that frequently leads to various attack vectors including denial of service conditions. The vulnerability manifests when an attacker sends a crafted request that exploits this validation gap, causing the underlying Cisco Database service to terminate unexpectedly.
The operational impact of this vulnerability extends beyond simple service disruption, as it specifically targets the management GUI interface that administrators rely upon for system maintenance and configuration. When the Cisco DB service crashes due to the malformed request, it effectively blocks administrative access to the entire Unified CM platform, creating a cascading effect that can severely hamper business continuity. This denial of service condition requires manual intervention to restore normal operation, including potential service restarts or system recovery procedures that can result in extended downtime and productivity losses. The attack vector is particularly concerning because it requires no authentication credentials, making it accessible to any remote attacker with network access to the affected system.
Organizations affected by this vulnerability should implement immediate mitigations to protect their unified communications infrastructure. Network segmentation and access controls can help limit exposure by restricting direct access to the UDS API endpoints from untrusted networks. Additionally, implementing firewall rules that filter suspicious requests and monitoring for unusual patterns in API traffic can help detect potential exploitation attempts. Cisco has released patches and software updates to address this vulnerability, which should be deployed immediately across all affected systems. The remediation process should include comprehensive testing in non-production environments before full deployment to ensure that updates do not introduce compatibility issues with existing configurations. Security teams should also consider implementing intrusion detection systems that can identify and alert on potential exploitation attempts targeting this specific vulnerability, aligning with ATT&CK technique T1499 which covers network denial of service attacks.