CVE-2000-0739 in Net Tools PKI Server
Summary
by MITRE
Directory traversal vulnerability in strong.exe program in NAI Net Tools PKI server 1.0 before HotFix 3 allows remote attackers to read arbitrary files via a .. (dot dot) attack in an HTTPS request to the enrollment server.
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Analysis
by VulDB Data Team • 06/08/2025
The vulnerability described in CVE-2000-0739 represents a critical directory traversal flaw within the strong.exe component of NAI Net Tools PKI server version 1.0 prior to HotFix 3. This issue specifically affects the enrollment server functionality that handles HTTPS requests, creating a pathway for remote attackers to access arbitrary files on the underlying system. The vulnerability stems from insufficient input validation mechanisms that fail to properly sanitize user-supplied data before processing file system operations. Attackers can exploit this weakness by crafting malicious HTTPS requests containing directory traversal sequences using the .. (dot dot) notation, which allows them to navigate beyond the intended directory boundaries and access restricted files.
The technical exploitation of this vulnerability falls under the category of CWE-22 - Improper Limitation of a Pathname to a Restricted Directory, which is a fundamental security flaw in path handling implementations. When the strong.exe program processes incoming HTTPS requests, it does not adequately validate or sanitize the file paths provided by clients, allowing malicious input to bypass normal access controls. The vulnerability specifically targets the enrollment server functionality, which typically handles certificate enrollment requests and related cryptographic operations. This creates a significant risk as the enrollment server often has elevated privileges and may be configured to access sensitive system files, configuration data, or cryptographic keys that should remain protected from unauthorized access.
The operational impact of this vulnerability extends beyond simple information disclosure, as it provides attackers with the capability to access potentially sensitive data that could include system configuration files, cryptographic key material, or other confidential information stored within the PKI server environment. The remote nature of the attack means that adversaries can exploit this flaw from outside the network perimeter without requiring local system access or authentication credentials. This vulnerability directly aligns with ATT&CK technique T1083 - File and Directory Discovery, as attackers can systematically explore the file system to identify and extract valuable information. The attack vector through HTTPS requests makes it particularly dangerous as it can traverse network firewalls and security boundaries that might otherwise protect the internal PKI infrastructure.
Mitigation strategies for this vulnerability should focus on implementing proper input validation and sanitization mechanisms within the strong.exe application. Organizations should immediately apply the available HotFix 3 patch released by NAI to address the directory traversal flaw. Additionally, network administrators should implement strict access controls and firewall rules that limit direct access to the enrollment server from untrusted networks. The implementation of web application firewalls and input validation layers can provide additional protection against similar attacks. Security monitoring should be enhanced to detect unusual file access patterns and directory traversal attempts in server logs. From a defense-in-depth perspective, organizations should consider implementing principle of least privilege access controls for PKI server components and regularly audit file system permissions to ensure that sensitive files remain protected from unauthorized access attempts.