CVE-2018-16170 in Remote Service
Summary
by MITRE
Directory traversal vulnerability in Cybozu Remote Service 3.0.0 to 3.1.8 for Windows allows remote authenticated attackers to read arbitrary files via unspecified vectors.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 04/27/2020
The vulnerability identified as CVE-2018-16170 represents a critical directory traversal flaw within the Cybozu Remote Service software version 3.0.0 through 3.1.8 on Windows platforms. This security weakness enables authenticated attackers to exploit the system and gain unauthorized access to arbitrary files stored on the target server. The vulnerability stems from insufficient input validation and improper handling of file path references within the application's file access mechanisms. Attackers leveraging this flaw can manipulate file path parameters to navigate beyond the intended directory boundaries and access sensitive system files, configuration data, or user information that should remain restricted. The issue affects organizations relying on Cybozu Remote Service for remote access management, potentially exposing critical infrastructure components to unauthorized data retrieval operations.
The technical implementation of this directory traversal vulnerability occurs when the application processes file requests without adequate sanitization of user-supplied input. This flaw typically manifests in scenarios where the software accepts file path parameters directly from authenticated users without proper validation or normalization of path sequences. Attackers can exploit this by crafting malicious requests containing directory traversal sequences such as "../" or "..\\" to move up directory levels and access files outside the intended application scope. The vulnerability's impact is amplified because it requires only authentication credentials, making it particularly dangerous in environments where legitimate users have access to the service. The flaw operates at the application layer and can be classified under CWE-22, which specifically addresses improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal attacks.
The operational consequences of CVE-2018-16170 extend beyond simple unauthorized file access, potentially enabling more sophisticated attack vectors and data exfiltration operations. An attacker with authenticated access can retrieve sensitive information including database connection strings, application configuration files, user credentials stored in plain text, system logs, and potentially system binaries that could aid in further exploitation. This vulnerability can facilitate lateral movement within networks where Cybozu Remote Service is deployed, as attackers might access files containing network configuration details or other sensitive data. The impact on organizational security is significant, as this flaw can lead to compliance violations, data breaches, and potential system compromise. Organizations may face regulatory penalties if sensitive data is accessed and exposed due to this vulnerability, particularly in industries governed by standards such as pci dss, hipaa, or gdpr.
Mitigation strategies for CVE-2018-16170 should prioritize immediate patching of affected Cybozu Remote Service installations to version 3.1.9 or later, which contains the necessary security fixes for the directory traversal vulnerability. Organizations should implement network segmentation and access controls to limit the exposure of the affected service to only authorized users and systems. Input validation should be strengthened at all application entry points to prevent malicious path sequences from being processed, with proper sanitization of file path parameters and enforcement of strict file access controls. Security monitoring should be enhanced to detect anomalous file access patterns that might indicate exploitation attempts, particularly focusing on unusual directory traversal activities. Network-based intrusion detection systems should be configured to alert on suspicious requests containing directory traversal sequences. Additionally, organizations should conduct regular security assessments and penetration testing to identify similar vulnerabilities within their network infrastructure, ensuring comprehensive protection against similar attack vectors that align with tactics described in the mitre att&ck framework under the privilege escalation and credential access domains. System administrators should also review and enforce least privilege principles for all accounts with access to the Cybozu Remote Service to minimize potential damage from successful exploitation attempts.