CVE-2017-18045 in DirectAdmin
Summary
by MITRE
JBMC DirectAdmin before 1.52, when the email_ftp_password_change setting is nonzero, allows remote attackers to obtain access or cause a denial of service (segfault) via an unspecified request.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 12/26/2019
The vulnerability identified as CVE-2017-18045 affects JBMC DirectAdmin versions prior to 1.52, specifically when the email_ftp_password_change setting is enabled. This configuration parameter controls whether email notifications are sent when FTP passwords are changed, creating a security exposure that remote attackers can exploit to gain unauthorized access or disrupt system availability. The flaw manifests through an unspecified request that triggers unexpected behavior in the application's processing logic, potentially leading to privilege escalation or system instability.
The technical implementation of this vulnerability stems from inadequate input validation and error handling within the password change functionality. When the email_ftp_password_change setting is set to a nonzero value, the system processes FTP password modifications in a manner that fails to properly sanitize or validate incoming requests. This weakness creates a path for attackers to craft malicious requests that can bypass normal authentication checks or trigger memory corruption issues. The vulnerability can result in either unauthorized access to system resources or a segmentation fault that causes the application to crash and terminate unexpectedly, leading to denial of service conditions.
From an operational perspective, this vulnerability presents significant risks to system administrators and organizations relying on DirectAdmin for web hosting management. The remote attack vector means that adversaries can exploit this weakness from any location without requiring physical access to the server. Successful exploitation could allow attackers to access FTP accounts, potentially leading to broader system compromise through credential theft or unauthorized file manipulation. The denial of service component further compounds the impact by making the management interface unavailable to legitimate users, disrupting normal hosting operations and potentially affecting multiple customer accounts simultaneously.
The vulnerability aligns with CWE-20, "Improper Input Validation," and CWE-125, "Out-of-bounds Read," as it involves inadequate validation of user-supplied data leading to memory access violations. From an adversarial perspective, this weakness maps to ATT&CK technique T1078, "Valid Accounts," as it could enable attackers to gain access to legitimate user accounts through password manipulation, and T1499, "Endpoint Denial of Service," for the segmentation fault exploitation. Organizations should immediately upgrade to DirectAdmin version 1.52 or later to address this vulnerability, while also implementing network-based controls such as firewall rules to restrict access to the DirectAdmin management interface and monitoring for suspicious request patterns that may indicate exploitation attempts.
Mitigation strategies should include immediate patch deployment, followed by comprehensive security auditing of all DirectAdmin installations to verify proper configuration of the email_ftp_password_change setting. System administrators should disable this setting if email notifications for FTP password changes are not required, as this effectively eliminates the attack surface. Additionally, implementing intrusion detection systems capable of identifying malformed requests targeting the affected functionality can provide early warning of exploitation attempts. Regular security assessments and vulnerability scanning should be conducted to identify similar weaknesses in other web-based management interfaces and ensure that input validation mechanisms are properly implemented across all application components.