CVE-2019-12696 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.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 12/29/2023
The CVE-2019-12696 vulnerability represents a critical security flaw within Cisco Firepower System Software Detection Engine that enables unauthenticated remote attackers to circumvent configured malware and file policies. This vulnerability specifically targets RTF and RAR file types, which are commonly used in phishing campaigns and malicious payload delivery. The flaw exists in the detection engine's ability to properly analyze and classify these file formats, creating a pathway for attackers to bypass security controls that should prevent the execution of potentially harmful content. The vulnerability demonstrates a fundamental weakness in the system's file inspection capabilities, particularly when dealing with office document formats and compressed archives that are frequently exploited in cyber attacks.
The technical implementation of this vulnerability stems from insufficient validation and analysis within the Firepower detection engine's processing pipeline. When RTF and RAR files are processed through the system, the engine fails to properly identify malicious characteristics or patterns that would typically trigger security alerts. This occurs due to incomplete parsing of file headers, metadata, or content structures that would normally flag suspicious behavior. The vulnerability is categorized under CWE-20, which represents improper input validation, and specifically relates to weaknesses in how the system handles file type identification and content analysis. Attackers can exploit this by crafting specially formatted RTF or RAR files that appear benign to the detection engine while containing malicious payloads or commands.
The operational impact of CVE-2019-12696 extends beyond simple policy bypass, as it fundamentally undermines the integrity of network security controls within organizations using Cisco Firepower systems. Organizations may experience unauthorized access to sensitive data, lateral movement within networks, and potential system compromise when attackers leverage this vulnerability to deliver malicious content. The remote nature of the attack means that threat actors can exploit this weakness from outside the network perimeter without requiring credentials or physical access. This vulnerability aligns with ATT&CK technique T1059, which covers command and scripting interpreter, as attackers can execute malicious code through bypassed file policies. The implications are particularly severe for enterprise environments where Firepower systems serve as primary network defense mechanisms.
Mitigation strategies for CVE-2019-12696 should include immediate application of Cisco's security patches and updates, which address the underlying validation flaws in the detection engine. Network administrators must also implement additional monitoring and logging mechanisms to detect anomalous file processing activities that may indicate exploitation attempts. Configuration changes should include stricter file type validation rules and enhanced inspection policies for RTF and RAR files. Organizations should consider deploying supplementary security controls such as sandboxing solutions and advanced threat detection systems to provide defense-in-depth against attacks that may exploit this vulnerability. The mitigation approach should also involve regular security assessments and vulnerability scanning to ensure that all network defense systems maintain adequate protection against similar weaknesses in file inspection capabilities.