CVE-2008-0604 in XLight FTP Server
Summary
by MITRE
The LDAP authentication feature in XLight FTP Server before 2.83, when used with some unspecified LDAP servers, does not check for blank passwords, which allows remote attackers to bypass intended access restrictions.
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Analysis
by VulDB Data Team • 03/02/2018
The vulnerability identified as CVE-2008-0604 represents a critical authentication flaw within the XLight FTP Server software ecosystem. This issue specifically targets the Lightweight Directory Access Protocol authentication mechanism that many FTP servers utilize to verify user credentials against directory services. The vulnerability exists in versions prior to 2.83 and manifests when the server interacts with certain LDAP implementations, creating a significant security gap that undermines the intended access control measures. The flaw lies in the server's failure to properly validate authentication credentials, particularly when dealing with blank or null password inputs.
The technical implementation of this vulnerability stems from inadequate input validation within the LDAP authentication module of XLight FTP Server. When a user attempts to authenticate through LDAP, the server should verify that the provided credentials meet minimum security requirements including non-empty password validation. However, the vulnerable implementation allows authentication requests to proceed even when no password is provided or when a blank password is submitted. This behavior creates an authentication bypass scenario where malicious actors can gain unauthorized access without proper credentials. The vulnerability is particularly concerning because it operates at the authentication layer, meaning it can be exploited to gain access to the entire FTP server and potentially underlying network resources.
From an operational impact perspective, this vulnerability exposes systems running vulnerable versions of XLight FTP Server to significant risk of unauthorized access and data compromise. Attackers can exploit this weakness to bypass authentication entirely, potentially gaining read, write, or administrative access to FTP server resources. The vulnerability affects the fundamental security principle of authentication, which is a core component of the CIA triad in information security. Organizations using affected versions of XLight FTP Server may experience unauthorized data access, potential data exfiltration, system compromise, and violations of regulatory compliance requirements such as those outlined in pci dss and iso 27001 standards. The impact extends beyond immediate access violations to include potential lateral movement within networks where FTP servers serve as entry points for broader attacks.
The vulnerability aligns with CWE-254, which addresses 'Security Misconfiguration' in authentication mechanisms, and relates to ATT&CK technique T1110.001 for 'Brute Force: Password Guessing' as attackers can exploit this weakness to bypass the authentication process entirely. Mitigation strategies include immediate upgrade to XLight FTP Server version 2.83 or later, which contains the necessary authentication validation fixes. Organizations should also implement additional security controls such as network segmentation to limit access to FTP servers, enable strong authentication mechanisms including multi-factor authentication, and conduct regular vulnerability assessments to identify similar issues. The fix typically involves implementing proper input validation for password fields within the LDAP authentication module, ensuring that blank or null passwords are rejected before authentication processing occurs. Security teams should also consider implementing monitoring and logging for authentication events to detect potential exploitation attempts and establish incident response procedures to address successful breaches.