CVE-2017-12250 in Wide Area Application Services
Summary
by MITRE
A vulnerability in the HTTP web interface for Cisco Wide Area Application Services (WAAS) could allow an unauthenticated, remote attacker to cause an HTTP Application Optimization (AO) related process to restart, causing a partial denial of service (DoS) condition. The vulnerability is due to lack of input validation of user-supplied input parameters within an HTTP request. An attacker could exploit this vulnerability by sending a crafted HTTP request through the targeted device. An exploit could allow the attacker to cause a DoS condition due to a process unexpectedly restarting. The WAAS could drop traffic during the brief time the process is restarting. Cisco Bug IDs: CSCvc63048.
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Analysis
by VulDB Data Team • 01/13/2021
The vulnerability identified as CVE-2017-12250 resides within Cisco Wide Area Application Services (WAAS) products, specifically affecting the HTTP web interface component that manages application optimization processes. This weakness represents a critical security flaw that undermines the reliability and availability of network services. The vulnerability manifests as a lack of proper input validation mechanisms within the HTTP request processing pipeline, creating an exploitable condition that can be leveraged by remote attackers without requiring authentication credentials. The affected WAAS devices operate as application optimization appliances that sit between network endpoints to improve application performance, making this vulnerability particularly concerning for enterprise network infrastructure. The Cisco Bug ID CSCvc63048 documents this specific flaw which was discovered within the HTTP interface implementation of the WAAS platform, where user-supplied parameters are not adequately validated before being processed by the system's internal components.
The technical exploitation of this vulnerability occurs through the injection of malformed HTTP requests that contain specially crafted input parameters designed to trigger the flawed validation logic. When the WAAS device receives such a request, the insufficient input validation causes the HTTP Application Optimization process to behave unpredictably, ultimately leading to an unexpected process restart. This restart event is not gracefully handled by the system, resulting in temporary service disruption that manifests as a partial denial of service condition. The process restart creates a brief window during which the WAAS appliance drops network traffic, effectively disrupting application performance for users accessing services through the optimized network paths. The vulnerability stems from CWE-20, which specifically addresses improper input validation in software applications, where the system fails to properly validate or sanitize user-supplied data before processing it. This weakness allows attackers to manipulate the application's execution flow through carefully constructed inputs that exploit the missing validation checks.
The operational impact of this vulnerability extends beyond simple service disruption to potentially affect business continuity and network performance across enterprise environments. Organizations relying on WAAS appliances for application optimization may experience intermittent service degradation or complete loss of optimization capabilities during the brief periods when processes restart. Network administrators face the challenge of maintaining service availability while monitoring for potential exploitation attempts, as the vulnerability can be triggered remotely without any authentication requirements. The partial DoS condition affects the quality of service for applications that depend on WAAS optimization, potentially leading to degraded user experience, slower application response times, and increased network latency. This vulnerability aligns with ATT&CK technique T1499.004, which describes the use of application or system exploitation to cause denial of service conditions, and demonstrates how weaknesses in web interface implementations can be leveraged to create operational disruptions.
Mitigation strategies for CVE-2017-12250 should prioritize immediate implementation of vendor-provided security patches and updates to address the input validation deficiencies in the WAAS HTTP interface. Network administrators should ensure that all WAAS appliances are updated to versions containing the necessary fixes for this vulnerability, which typically involve enhanced input validation mechanisms and improved error handling for HTTP request parameters. Access control measures should be implemented to restrict access to the WAAS HTTP interface to trusted administrative networks only, reducing the attack surface available to potential remote attackers. Network monitoring solutions should be configured to detect and alert on unusual HTTP request patterns that may indicate exploitation attempts, particularly those involving malformed parameters or unusual request sequences. Additionally, organizations should consider implementing network segmentation strategies that isolate WAAS appliances from critical network segments, limiting the potential impact of successful exploitation attempts. The remediation process should include thorough testing of updated firmware to ensure that the security patches do not introduce compatibility issues with existing network services or application optimization configurations.