CVE-2017-18467 in cPanel
Summary
by MITRE
cPanel before 62.0.17 allows access to restricted resources because of a URL filtering error (SEC-229).
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Analysis
by VulDB Data Team • 07/20/2020
The vulnerability identified as CVE-2017-18467 represents a critical access control flaw within cPanel software versions prior to 62.0.17, specifically categorized under CWE-284 Access Control Issues. This security weakness stems from an inadequate URL filtering mechanism that fails to properly validate and sanitize user input before granting access to protected system resources. The flaw essentially allows unauthorized users to bypass intended access restrictions and gain access to restricted functionality within the cPanel interface, potentially exposing sensitive administrative controls and system information to malicious actors. Such a vulnerability directly contravenes the principle of least privilege and demonstrates a fundamental failure in the application's authorization mechanisms.
The technical implementation of this vulnerability involves a URL filtering error that permits crafted malicious requests to traverse the intended access control boundaries. When users submit requests through the web interface, the system should validate that the requested resources are appropriate for the authenticated user's permissions level. However, due to insufficient input validation and filtering, maliciously constructed URLs can bypass these security checks, allowing access to restricted administrative functions. This type of flaw falls under the ATT&CK technique T1078 Valid Accounts, as it enables unauthorized access to legitimate user accounts through exploitation of access control weaknesses rather than through credential theft or brute force attacks. The vulnerability essentially creates a backdoor path through the application's security architecture, allowing attackers to escalate privileges and access resources they should not be authorized to view or modify.
The operational impact of CVE-2017-18467 is severe and multifaceted, as it can lead to complete system compromise when exploited by malicious actors. An attacker who successfully exploits this vulnerability can gain access to sensitive administrative controls, potentially allowing them to modify system configurations, create or delete user accounts, access email accounts, manipulate databases, and perform other administrative functions. This access could result in data breaches, system corruption, service disruption, and potential lateral movement within the network if the compromised cPanel instance serves multiple domains or accounts. The vulnerability affects organizations that rely on cPanel for hosting management, making it particularly dangerous for web hosting providers and businesses that manage multiple client accounts through a single control panel interface. The impact extends beyond immediate security compromise to include potential regulatory compliance violations, reputational damage, and financial losses associated with data breaches and system downtime.
Mitigation strategies for CVE-2017-18467 center on immediate software updates and comprehensive security hardening measures. Organizations should prioritize upgrading to cPanel version 62.0.17 or later, which contains the necessary patches to address the URL filtering error. Additionally, implementing network-level security controls such as web application firewalls and access control lists can provide additional defense-in-depth layers. Security administrators should also conduct thorough audits of existing cPanel installations to identify any potential exploitation attempts and review access logs for suspicious activity. The implementation of principle of least privilege should be enforced at all levels of access control, ensuring that users only receive the minimum permissions necessary for their legitimate functions. Regular security assessments and vulnerability scanning should be performed to identify similar access control weaknesses within the broader application ecosystem. Organizations should also consider implementing intrusion detection systems to monitor for anomalous access patterns that might indicate exploitation attempts of this type of vulnerability.