CVE-2018-0370 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 cause one of the detection engine processes to run out of memory and thus slow down traffic processing. The vulnerability is due to improper handling of traffic when the Secure Sockets Layer (SSL) inspection policy is enabled. An attacker could exploit this vulnerability by sending malicious traffic through an affected device. An exploit could allow the attacker to increase the resource consumption of a single instance of the Snort detection engine on an affected device. This will lead to performance degradation and eventually the restart of the affected Snort process. Cisco Bug IDs: CSCvi09219, CSCvi29845.
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Analysis
by VulDB Data Team • 11/26/2024
The vulnerability identified as CVE-2018-0370 resides within the detection engine of Cisco Firepower System Software, representing a critical security flaw that enables unauthenticated remote attackers to manipulate system resources through carefully crafted network traffic. This weakness specifically manifests when the Secure Sockets Layer SSL inspection policy is active, creating a pathway for malicious actors to exploit improper traffic handling mechanisms that ultimately result in memory exhaustion within the Snort detection engine processes. The vulnerability stems from inadequate resource management during SSL inspection operations, where the system fails to properly validate or limit the memory allocation required for processing encrypted traffic flows.
The technical exploitation of this vulnerability occurs through the deliberate injection of malicious traffic patterns that trigger the SSL inspection functionality on affected Cisco Firepower devices. When the system processes these crafted packets, the detection engine fails to implement proper memory bounds checking or resource limiting mechanisms, allowing memory consumption to spiral out of control. This improper handling creates a condition where individual Snort engine instances gradually consume available memory resources until system performance degrades significantly. The vulnerability specifically targets the Snort detection engine architecture, which serves as the core traffic analysis component within Cisco Firepower systems, making it a critical point of failure for network security operations.
The operational impact of CVE-2018-0370 extends beyond simple performance degradation to potentially disrupt network security operations entirely. As memory consumption increases, the affected Snort processes may eventually crash or restart automatically, creating gaps in network monitoring and security enforcement. This disruption can lead to missed threat detections, reduced network visibility, and potential security breaches during the restart periods when the system is most vulnerable. The vulnerability affects the availability and reliability of network security services, as legitimate traffic processing becomes impaired while the system attempts to recover from the memory exhaustion condition. Organizations relying on Cisco Firepower for network protection face significant operational risks including potential service interruptions and compromised security posture during exploitation attempts.
Mitigation strategies for this vulnerability should focus on immediate patch application through Cisco's official security advisories, which typically address the root cause through improved memory management and resource allocation controls within the SSL inspection module. Network administrators should also consider temporarily disabling SSL inspection policies on affected systems until patches are deployed, though this approach reduces security coverage and should be implemented cautiously. Additional protective measures include implementing traffic rate limiting, monitoring for unusual memory consumption patterns, and establishing automated alerting for detection engine performance degradation. The vulnerability aligns with CWE-129, which addresses improper handling of memory allocation and resource limits, and maps to ATT&CK technique T1499.004 for network denial of service attacks. Organizations should also review their incident response procedures to ensure rapid detection and remediation of memory exhaustion conditions that could indicate exploitation of this vulnerability.