CVE-2017-6674 in Firepower System Software
Summary
by MITRE
A vulnerability in the feature-license management functionality of Cisco Firepower System Software could allow an unauthenticated, remote attacker to bypass URL filters that have been configured for an affected device. More Information: CSCvb16413. Known Affected Releases: 6.0.1 6.1.0 6.2.0 6.2.1. Known Fixed Releases: 6.2.1 6.2.0.1 6.1.0.2.
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Analysis
by VulDB Data Team • 12/27/2020
The vulnerability identified as CVE-2017-6674 resides within the feature-license management functionality of Cisco Firepower System Software, representing a critical security flaw that undermines the integrity of web content filtering mechanisms. This weakness specifically affects versions 6.0.1, 6.1.0, 6.2.0, and 6.2.1 of the software, creating a significant attack surface that could be exploited by remote threat actors without requiring authentication credentials. The vulnerability stems from improper validation of license states and feature permissions, which allows malicious entities to manipulate the system's behavior and bypass configured URL filtering rules. This flaw directly impacts the core security posture of organizations relying on Cisco Firepower devices for network protection and content control.
The technical implementation of this vulnerability involves a flaw in how the system processes and validates license information during feature activation and access control decisions. When a device processes license validation requests, the software fails to properly enforce the boundaries of configured URL filtering policies, enabling an attacker to exploit this gap in the authorization mechanism. The issue manifests as an insufficient access control check that permits unauthorized access to restricted content filtering features, effectively allowing attackers to circumvent security policies that should prevent access to malicious or inappropriate websites. This vulnerability operates at the application layer and can be exploited through network-based attacks that do not require any prior authentication or privileged access to the system.
From an operational impact perspective, this vulnerability creates a severe risk to network security posture and organizational compliance requirements. Organizations utilizing Cisco Firepower devices for web content filtering may experience unauthorized access to restricted websites, potentially exposing their networks to malware distribution, data exfiltration attempts, and other malicious activities. The bypass of configured URL filters could lead to significant security incidents including insider threats, phishing attacks, and unauthorized access to sensitive corporate resources. Security administrators may face challenges in maintaining audit compliance and demonstrating proper network protection measures, as the vulnerability allows attackers to operate undetected within the network perimeter. The attack vector is particularly concerning because it requires no authentication, making it accessible to any remote attacker with network connectivity to the affected system.
The mitigation strategy for CVE-2017-6674 involves implementing the vendor-provided security updates and patches released in versions 6.2.1, 6.2.0.1, and 6.1.0.2, which address the underlying license validation and access control implementation flaws. Organizations should prioritize immediate deployment of these patches across all affected Firepower devices and conduct thorough testing to ensure compatibility with existing network configurations. Network administrators should also consider implementing additional monitoring measures to detect potential exploitation attempts, including reviewing firewall logs for unusual access patterns and monitoring for unauthorized URL filtering bypass attempts. The vulnerability aligns with CWE-284 Access Control Issues, specifically addressing improper access control mechanisms that allow privilege escalation or unauthorized access to restricted resources. From an ATT&CK framework perspective, this vulnerability maps to techniques involving privilege escalation and defense evasion, as attackers can bypass security controls without requiring elevated privileges. Organizations should also consider implementing network segmentation and additional access controls to minimize potential impact if exploitation occurs, while maintaining comprehensive security monitoring to detect and respond to any suspicious network activity that may indicate attempted exploitation of this vulnerability.