CVE-2018-0283 in Firepower System Software
Summary
by MITRE
A vulnerability in the detection engine of Cisco Firepower System Software could allow an unauthenticated, remote attacker to restart an instance of the Snort detection engine on an affected device, resulting in a brief denial of service (DoS) condition. The vulnerability is due to the incorrect handling of Transport Layer Security (TLS) TCP connection setup for the affected software. An attacker could exploit this vulnerability by sending crafted TLS traffic to an affected device. A successful exploit could allow the attacker to cause the Snort detection engine on the affected device to restart, resulting in a DoS condition. Cisco Bug IDs: CSCvg99327.
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Analysis
by VulDB Data Team • 11/26/2024
The vulnerability described in CVE-2018-0283 represents a significant security flaw within Cisco Firepower System Software that specifically targets the Snort detection engine component. This issue arises from improper handling of Transport Layer Security TCP connection setup processes, creating an exploitable condition that allows remote attackers to disrupt system operations without requiring authentication credentials. The flaw exists within the detection engine's processing logic for TLS connections, making it particularly dangerous as it can be leveraged by attackers from remote locations without needing physical access or valid user credentials. The vulnerability specifically affects Cisco Firepower devices that utilize the Snort detection engine, creating a potential vector for service disruption attacks that could impact network security operations.
The technical implementation of this vulnerability stems from the incorrect processing of TLS TCP connection establishment sequences within the Firepower system software. When legitimate TLS traffic is sent to an affected device, the system fails to properly validate or handle the connection setup process, leading to unexpected behavior in the Snort detection engine. This improper handling manifests as an automatic restart of the Snort engine instance, which temporarily interrupts the device's ability to perform network traffic analysis and intrusion detection functions. The flaw essentially creates a condition where crafted malicious TLS traffic can trigger an unintended system restart, effectively causing a brief denial of service state. The vulnerability is particularly concerning because it operates at the transport layer and can be exploited without authentication, making it accessible to any remote attacker who can reach the targeted device.
From an operational impact perspective, this vulnerability creates a substantial risk for network security infrastructure as it allows attackers to perform denial of service attacks against Cisco Firepower devices. The restart of the Snort detection engine results in a temporary loss of network monitoring capabilities, potentially leaving the network exposed to threats during the brief interruption period. This disruption can be particularly damaging in environments where continuous network monitoring is critical for security operations, as the system temporarily loses its ability to detect and respond to potential security incidents. The vulnerability's remote exploitability means that attackers can target these devices from anywhere on the network, making it a significant concern for organizations that rely on Firepower systems for their network security posture. The brief nature of the DoS condition does not diminish its impact, as even temporary interruptions in security monitoring can create windows of vulnerability for malicious actors.
Organizations affected by CVE-2018-0283 should implement immediate mitigation strategies to protect their network infrastructure from potential exploitation. The primary recommendation involves applying the relevant security patches provided by Cisco to address the TLS connection handling flaw in the Firepower system software. Additionally, network administrators should consider implementing network segmentation and access controls to limit the exposure of Firepower devices to untrusted networks. The vulnerability aligns with CWE-20, which describes improper input validation, and could potentially be categorized under ATT&CK technique T1499.004 for network disruption attacks. Organizations should also monitor their network traffic for unusual TLS connection patterns that might indicate exploitation attempts, and maintain updated incident response procedures to quickly address any potential DoS events. The mitigation approach should include regular vulnerability assessments and network monitoring to ensure that the system remains protected against similar vulnerabilities in the future.