CVE-2002-0222 in EServ
Summary
by MITRE
Etype Eserv 2.97 allows remote attackers to redirect traffic to other sites (aka FTP bounce) via the PORT command.
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Analysis
by VulDB Data Team • 09/21/2025
The vulnerability identified as CVE-2002-0222 affects Etype Eserv 2.97, a web server software that implements the File Transfer Protocol. This security flaw represents a significant weakness in the server's handling of FTP connections, specifically within the PORT command functionality. The vulnerability enables remote attackers to manipulate the server's network behavior by exploiting how it processes incoming connection requests, creating an avenue for traffic redirection that can be leveraged for malicious purposes.
The technical implementation of this vulnerability stems from improper validation and handling of the PORT command in the FTP protocol. When a client sends a PORT command to the Eserv 2.97 server, the server fails to properly validate the destination address specified in the command. This allows an attacker to provide a malicious address that redirects the server's outbound connections to arbitrary destinations, effectively enabling what is known as FTP bounce attacks. The flaw exists at the protocol implementation level where the server does not adequately sanitize or verify the network addresses provided by clients during FTP session establishment.
From an operational impact perspective, this vulnerability poses substantial risks to network security and data integrity. Attackers can exploit this weakness to redirect FTP traffic through the compromised server, potentially using it as a pivot point for accessing internal network resources that would otherwise be protected by firewalls. The attack can be used to bypass network restrictions, gain access to systems that are normally unreachable, or even facilitate further attacks by establishing connections to other services. This type of vulnerability undermines the fundamental security assumptions of network isolation and can lead to unauthorized data access, exfiltration, or compromise of sensitive information.
The vulnerability aligns with CWE-284, which addresses improper access control in software implementations, and represents a classic example of how protocol-level flaws can create security breaches. From an ATT&CK framework perspective, this vulnerability maps to techniques involving port knocking and network tunneling, where adversaries leverage legitimate network protocols to establish covert communication channels. The attack pattern falls under the category of network infiltration and can be classified as a form of protocol manipulation that exploits trust relationships between network services.
Mitigation strategies for this vulnerability require immediate patching of the affected Eserv 2.97 software to address the flawed PORT command handling. Organizations should implement network segmentation to limit the exposure of FTP services and consider disabling the PORT command entirely if it is not essential for operations. Additional security measures include implementing network monitoring to detect suspicious FTP traffic patterns, configuring firewalls to restrict FTP traffic, and establishing proper access controls for FTP services. The remediation process should also involve comprehensive security testing to verify that the patched software correctly handles all FTP commands and does not introduce new vulnerabilities during the update process.