CVE-2002-0538 in Enterprise Firewall
Summary
by MITRE
FTP proxy in Symantec Raptor Firewall 6.5.3 and Enterprise 7.0 rewrites an FTP server s "FTP PORT" responses in a way that allows remote attackers to redirect FTP data connections to arbitrary ports, a variant of the "FTP bounce" vulnerability.
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Analysis
by VulDB Data Team • 06/21/2024
The vulnerability identified as CVE-2002-0538 represents a critical flaw in the Symantec Raptor Firewall series, specifically affecting versions 6.5.3 and 7.0. This security weakness resides within the firewall's FTP proxy implementation and constitutes a variant of the well-known FTP bounce attack vector that has plagued network security systems for decades. The vulnerability exploits the fundamental design of FTP protocol handling within the firewall environment, creating a pathway for malicious actors to manipulate network traffic flows.
The technical flaw manifests in how the Symantec Raptor Firewall processes FTP PORT command responses during proxy operations. When an FTP client establishes a connection through the firewall, the system rewrites the server's PORT response in a manner that fails to properly validate or restrict the target port numbers for data connections. This improper handling allows attackers to craft malicious FTP commands that redirect data connections to arbitrary ports on the network, effectively bypassing the firewall's intended security boundaries. The vulnerability specifically affects the FTP proxy functionality that operates between the client and server, creating a tunneling mechanism that can be exploited to gain unauthorized access to internal network resources.
The operational impact of this vulnerability extends beyond simple port redirection, as it enables attackers to perform various malicious activities including port scanning, service enumeration, and potential data exfiltration. By redirecting FTP data connections to arbitrary ports, attackers can effectively use the firewall as a conduit to probe internal network services that would normally be protected from external access. This creates a significant risk for organizations relying on the firewall for network segmentation and access control, as the vulnerability essentially allows unauthorized lateral movement within the network infrastructure. The attack can be particularly devastating when combined with other reconnaissance techniques, as it provides a method for attackers to map internal network topology and identify vulnerable services.
This vulnerability aligns with CWE-284, which addresses improper access control in network security systems, and demonstrates the classic pattern of insufficient input validation in proxy server implementations. From an ATT&CK framework perspective, this flaw maps to techniques involving port scanning and network discovery, as well as privilege escalation through proxy manipulation. Organizations using Symantec Raptor Firewall should consider immediate mitigation strategies including firmware updates from the vendor, network segmentation, and implementation of additional access control measures. The vulnerability also highlights the importance of proper FTP protocol handling in security appliances and serves as a reminder of the risks associated with legacy firewall implementations that may not adequately address modern threat landscapes. Network administrators should implement monitoring solutions to detect unusual FTP traffic patterns and consider disabling FTP proxy functionality until proper patches are applied to ensure comprehensive protection against this and similar variants of FTP bounce attacks.