CVE-2019-12697 in Firepower System Software
Summary
by MITRE
Multiple vulnerabilities in the Cisco Firepower System Software Detection Engine could allow an unauthenticated, remote attacker to bypass configured Malware and File Policies for RTF and RAR file types. For more information about these vulnerabilities, see the Details section of this advisory.
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Analysis
by VulDB Data Team • 12/29/2023
The vulnerability identified as CVE-2019-12697 affects Cisco Firepower System Software Detection Engine, representing a critical security flaw that undermines the integrity of malware protection mechanisms within the network security infrastructure. This vulnerability resides in the detection engine's processing logic for specific file types, creating a pathway for malicious actors to circumvent security controls without requiring authentication or network access privileges. The affected system operates as a network-based intrusion prevention system that monitors and blocks malicious traffic patterns, making this weakness particularly dangerous as it allows attackers to bypass configured malware and file policies that are essential for protecting enterprise networks from sophisticated threats.
The technical flaw manifests in the detection engine's handling of Rich Text Format and RAR file types, where the software fails to properly validate or analyze these specific file formats during inspection processes. This validation failure occurs within the malware detection and file policy enforcement mechanisms, allowing specially crafted malicious files to slip through the security controls undetected. The vulnerability exploits a gap in the engine's file type recognition and classification algorithms, enabling attackers to craft payloads that appear benign to the system's inspection protocols while containing actual malicious content. This represents a classic example of a bypass vulnerability where the security controls are circumvented through manipulation of the inspection process rather than direct exploitation of system vulnerabilities.
Operationally, this vulnerability creates significant risk for organizations relying on Cisco Firepower systems for network security protection, as it allows remote attackers to deliver malicious content that would normally be blocked by configured policies. The impact extends beyond simple bypass of security controls to potentially enable more sophisticated attack vectors including malware delivery, data exfiltration, and lateral movement within compromised networks. Attackers can leverage this vulnerability to deliver malicious RTF and RAR files that contain exploits, backdoors, or other malicious payloads that would otherwise be detected and prevented by the system's configured security policies. This creates a false sense of security for network administrators who believe their malware protection systems are functioning correctly while malicious traffic continues to flow through the network undetected.
Organizations should implement immediate mitigations including applying the latest Cisco software patches and updates that address the detection engine validation issues, configuring additional network segmentation and monitoring controls to detect anomalous file transfer patterns, and implementing supplementary security measures such as email filtering and web proxy controls to provide layered protection. The vulnerability aligns with CWE-20 Improper Input Validation and follows attack patterns described in the ATT&CK framework under T1059 Command and Scripting Interpreter and T1078 Valid Accounts, as attackers can leverage the bypass to execute malicious code and maintain persistence within networks. Network administrators should also conduct thorough security assessments of their Firepower systems to identify any potential exploitation attempts and implement enhanced monitoring for suspicious file transfer activities that may indicate exploitation of this vulnerability.