CVE-2001-1463 in Serv-U
Summary
by MITRE
The remote administration client for RhinoSoft Serv-U 3.0 sends the user password in plaintext even when S/KEY One-Time Password (OTP) authentication is enabled, which allows remote attackers to sniff passwords.
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Analysis
by VulDB Data Team • 11/17/2024
The vulnerability described in CVE-2001-1463 represents a critical security flaw in the RhinoSoft Serv-U 3.0 FTP server implementation that directly violates fundamental principles of secure authentication protocols. This issue manifests in the remote administration client component where the system fails to properly implement the security measures associated with S/KEY One-Time Password authentication, creating a significant attack surface that exposes user credentials to interception.
The technical flaw occurs within the authentication mechanism of the Serv-U server's remote administration interface where the system sends user passwords in plaintext format regardless of the authentication method selected. When S/KEY OTP authentication is enabled, the protocol is designed to provide enhanced security through the use of one-time passwords that are mathematically derived from a shared secret and a counter value. However, the Serv-U 3.0 implementation fails to respect this security model and instead transmits the actual user password in clear text over the network, effectively nullifying the security benefits of the OTP system.
This vulnerability creates a severe operational impact by enabling man-in-the-middle attacks and network traffic interception scenarios where attackers can easily capture authentication credentials during transmission. The plaintext password transmission violates the principle of least privilege and provides attackers with direct access to user accounts, potentially leading to unauthorized system access, data breaches, and privilege escalation within the affected environment. According to CWE-312, this represents a clear violation of data protection principles where sensitive information is exposed during transmission.
The attack vector for this vulnerability aligns with ATT&CK technique T1075 which describes the use of legitimate credentials for unauthorized access. Network sniffing tools can easily capture the plaintext passwords as they traverse the network, making this a particularly dangerous vulnerability for environments where network traffic is not properly secured or encrypted. The impact extends beyond simple credential theft to potentially enable broader compromise of the affected server and its associated network resources.
Organizations should immediately implement mitigations including network segmentation to isolate critical administrative interfaces, deployment of encrypted communication channels such as SSL/TLS for remote administration, and implementation of network monitoring to detect anomalous traffic patterns. The vulnerability also highlights the importance of proper security protocol implementation and adherence to security standards such as those outlined in NIST SP 800-57 for cryptographic key management and authentication protocols. Additionally, upgrading to newer versions of the Serv-U software that properly implement S/KEY authentication or transitioning to more modern authentication mechanisms would provide comprehensive protection against this specific vulnerability.