CVE-2017-9001 in ClearPass
Summary
by MITRE
Aruba ClearPass 6.6.3 and later includes a feature called "SSH Lockout", which causes ClearPass to lock accounts with too many login failures through SSH. When this feature is enabled, an unauthenticated remote command execution vulnerability is present which could allow an unauthenticated user to execute arbitrary commands on the underlying operating system with "root" privilege level. This vulnerability is only present when a specific feature has been enabled. The SSH Lockout feature is not enabled by default, so only systems which have enabled this feature are vulnerable.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 03/13/2020
The vulnerability identified as CVE-2017-9001 affects Aruba ClearPass Policy Manager versions 6.6.3 and later, specifically when the SSH Lockout feature is enabled. This security flaw represents a critical remote code execution vulnerability that can be exploited by unauthenticated attackers to gain root-level privileges on the underlying operating system. The vulnerability emerges from the interaction between the SSH Lockout functionality and the command execution mechanisms within the ClearPass platform, creating an exploitable condition that bypasses normal authentication requirements.
The technical implementation of this vulnerability stems from improper input validation and privilege escalation within the SSH Lockout feature's code execution pathways. When enabled, the SSH Lockout mechanism creates a state where malicious input can trigger command injection attacks through the SSH protocol interface. This flaw allows an attacker to execute arbitrary commands with root privileges, effectively providing complete system compromise. The vulnerability is classified under CWE-78 as a "Improper Neutralization of Special Elements used in an OS Command" and aligns with ATT&CK technique T1059.001 for Command and Scripting Interpreter. The exploitation occurs because the system does not properly sanitize user inputs that are passed through to operating system commands, creating a direct path for command injection attacks.
The operational impact of this vulnerability is severe as it provides attackers with unrestricted access to the underlying operating system, enabling them to modify system files, install malware, create backdoors, and exfiltrate sensitive data. An attacker could potentially escalate privileges to gain full administrative control over the ClearPass server, which typically serves as a critical network access control platform managing authentication policies for enterprise networks. The vulnerability affects organizations that have explicitly enabled the SSH Lockout feature, making it particularly concerning for enterprises that may have enabled this security feature without fully understanding its potential attack surface implications. This issue directly impacts the CIA triad by compromising confidentiality, integrity, and availability of network access control services.
Mitigation strategies for CVE-2017-9001 should focus on immediate remediation actions including disabling the SSH Lockout feature if it is not essential for operations, applying the vendor-provided security patches, and implementing network segmentation to limit access to ClearPass servers. Organizations should also consider monitoring for suspicious SSH activity and implementing intrusion detection systems to identify potential exploitation attempts. The recommended approach includes disabling the vulnerable feature entirely, as the default installation does not enable SSH Lockout, making this a configuration management issue that organizations must address through proper security hardening practices. Additionally, implementing principle of least privilege access controls and regular security audits of network access control systems can help prevent exploitation of similar vulnerabilities in the future.