CVE-2019-1970 in Firepower Threat Defense
Summary
by MITRE
A vulnerability in the Secure Sockets Layer (SSL)/Transport Layer Security (TLS) protocol inspection engine of Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to bypass the configured file policies on an affected system. The vulnerability is due to errors when handling specific SSL/TLS messages. An attacker could exploit this vulnerability by sending crafted HTTP packets that would flow through an affected system. A successful exploit could allow the attacker to bypass the configured file policies and deliver a malicious payload to the protected network.
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Analysis
by VulDB Data Team • 11/26/2024
The vulnerability identified as CVE-2019-1970 resides within the SSL/TLS protocol inspection engine of Cisco Firepower Threat Defense software, representing a critical security flaw that undermines the fundamental integrity of network traffic filtering mechanisms. This vulnerability specifically targets the handling of SSL/TLS messages within the threat defense system, creating a pathway for unauthorized access that bypasses configured file policies. The flaw manifests when the system processes certain malformed or crafted SSL/TLS messages, allowing malicious actors to circumvent security controls that should prevent unauthorized file transfers and content delivery.
The technical exploitation of this vulnerability occurs through carefully crafted HTTP packets that traverse the affected Cisco Firepower system, where the SSL/TLS inspection engine fails to properly validate incoming SSL/TLS protocol messages. This processing error enables attackers to manipulate the inspection engine's behavior, effectively allowing malicious payloads to bypass the configured file policies that are designed to block suspicious or unauthorized file transfers. The vulnerability's impact extends beyond simple protocol inspection failure, as it fundamentally compromises the system's ability to enforce file access controls and content filtering policies that are essential for network security.
From an operational perspective, this vulnerability presents a severe risk to organizations relying on Cisco Firepower for network protection, as it allows remote attackers to bypass critical security controls without requiring authentication or privileged access. The attack vector is particularly concerning because it leverages standard network protocols that are commonly traversing firewalls and security appliances, making it difficult to detect and prevent. Organizations may experience unauthorized data exfiltration, malware delivery, or other malicious activities that bypass the security controls designed to protect their networks from such threats.
The vulnerability aligns with CWE-295, which addresses improper certificate validation in SSL/TLS implementations, and demonstrates how protocol inspection flaws can create bypass opportunities in security appliances. From an ATT&CK framework perspective, this vulnerability maps to techniques involving protocol manipulation and evasion of network defenses, specifically targeting the defense evasion and command and control phases of an attack lifecycle. The exploitation of this vulnerability could enable attackers to establish persistent access to networks, deliver malware payloads, or exfiltrate sensitive data while remaining undetected by traditional security controls.
Organizations should implement immediate mitigations including applying the latest Cisco security patches and updates to address the SSL/TLS inspection engine flaw, configuring additional network monitoring to detect anomalous SSL/TLS traffic patterns, and implementing network segmentation to limit the potential impact of successful exploitation. Security teams should also review and test their current file policy configurations to ensure proper enforcement of access controls, while monitoring for indicators of compromise that may suggest exploitation attempts. The vulnerability underscores the importance of maintaining up-to-date security appliances and implementing layered defense strategies that do not rely solely on a single point of failure for network protection.