CVE-2018-6695 in Threat Intelligence Exchange
Summary
by MITRE
SSH host keys generation vulnerability in the server in McAfee Threat Intelligence Exchange Server (TIE Server) 1.3.0, 2.0.x, 2.1.x, 2.2.0 allows man-in-the-middle attackers to spoof servers via acquiring keys from another environment.
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Analysis
by VulDB Data Team • 03/29/2020
The CVE-2018-6695 vulnerability represents a critical security flaw in McAfee Threat Intelligence Exchange Server versions 1.3.0 through 2.2.0 that specifically targets the Secure Shell host key generation process. This vulnerability stems from the improper implementation of cryptographic key generation mechanisms within the TIE Server's SSH service, creating a scenario where attackers can potentially impersonate legitimate servers through man-in-the-middle attacks. The flaw manifests when the system generates predictable or compromised host keys, undermining the fundamental trust model that SSH relies upon for secure remote access. According to CWE-327, this vulnerability directly relates to the use of weak cryptographic algorithms or improper cryptographic implementations, which creates a pathway for adversaries to establish fraudulent server identities. The vulnerability is particularly concerning as it allows attackers to acquire legitimate SSH keys from different environments and use them to deceive clients into connecting to compromised servers rather than the intended legitimate systems.
The technical implementation of this vulnerability involves the predictable or insecure generation of SSH host keys within the McAfee TIE Server software. When the SSH service initializes, it should generate cryptographically secure random keys that are unique to each server instance. However, in affected versions, the key generation process either uses insufficient entropy sources, employs weak random number generators, or follows predictable patterns that make it possible for attackers to reproduce or acquire these keys. This weakness allows an attacker who gains access to valid keys from one environment to deploy them in another environment, effectively enabling server impersonation. The vulnerability operates at the protocol level where SSH server keys are used to authenticate the server to connecting clients, and when these keys are compromised or predictable, the entire authentication mechanism fails. The flaw aligns with ATT&CK technique T1566.002 which describes the use of credential dumping and key compromise to establish persistence and conduct man-in-the-middle attacks.
The operational impact of CVE-2018-6695 extends far beyond simple authentication bypasses, creating significant risks for organizations relying on McAfee TIE Server for threat intelligence management and security operations. When attackers can successfully spoof SSH servers, they gain the ability to intercept and potentially modify communications between clients and the threat intelligence server, potentially accessing sensitive threat data, malware samples, or security configurations. The vulnerability undermines the integrity of the entire security infrastructure by allowing unauthorized parties to establish trusted connections that appear legitimate to end users and automated systems. Organizations may experience data exfiltration, command execution, or other malicious activities that leverage the compromised SSH server identity. The attack vector is particularly dangerous because it can be executed without requiring direct network access to the target server, as attackers can simply acquire keys from compromised environments and deploy them in target systems. This vulnerability affects the confidentiality, integrity, and availability of security data and processes that depend on secure SSH communications.
Mitigation strategies for CVE-2018-6695 should focus on immediate remediation through official vendor patches and comprehensive key regeneration procedures. Organizations must update their McAfee TIE Server installations to versions that address the cryptographic key generation weakness, typically through security patches provided by McAfee. System administrators should implement immediate key rotation procedures across all affected server instances, generating new SSH host keys using properly configured cryptographic random number generators with sufficient entropy sources. Network segmentation and monitoring should be enhanced to detect anomalous SSH connection patterns that might indicate key compromise attempts. The vulnerability highlights the importance of proper cryptographic implementation practices and adherence to security standards such as NIST SP 800-90A for random number generation and FIPS 140-2 for cryptographic module validation. Additionally, organizations should implement certificate-based authentication methods as alternative security measures and consider using SSH key management solutions that can automatically detect and respond to key compromise scenarios. Regular security assessments should include verification of cryptographic implementations and key management practices to prevent similar vulnerabilities from emerging in other security infrastructure components.