CVE-2006-4948 in TFTP Server TFTPDWIN
Summary
by MITRE
Stack-based buffer overflow in tftpd.exe in ProSysInfo TFTP Server TFTPDWIN 0.4.2 and earlier allows remote attackers to execute arbitrary code or cause a denial of service via a long file name. NOTE: the provenance of this information is unknown; the details are obtained from third party information.
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Analysis
by VulDB Data Team • 03/04/2017
The vulnerability identified as CVE-2006-4948 represents a critical stack-based buffer overflow in the tftpd.exe component of ProSysInfo TFTP Server TFTPDWIN version 0.4.2 and earlier. This flaw exists within the Trivial File Transfer Protocol server implementation, which is commonly used for transferring files over network connections. The vulnerability specifically manifests when the server processes file requests containing excessively long file names, creating an exploitable condition that can be leveraged by remote attackers to gain unauthorized system access or disrupt service availability.
The technical nature of this buffer overflow stems from inadequate input validation within the TFTP server's file name handling mechanism. When a client sends a file request with an overly long file name, the server fails to properly bounds-check the input before copying it into a fixed-size stack buffer. This classic programming error allows an attacker to overwrite adjacent memory locations, potentially corrupting the stack frame and executing arbitrary code with the privileges of the TFTP server process. The vulnerability is categorized under CWE-121 as a stack-based buffer overflow, which directly enables code execution through manipulation of the program's execution flow.
The operational impact of this vulnerability extends beyond simple denial of service to encompass full system compromise. Remote attackers can exploit this weakness to execute malicious code on vulnerable systems, potentially gaining unauthorized access to sensitive data, establishing persistent backdoors, or using the compromised server as a launching point for further attacks within the network. The TFTP protocol's typical use in network boot processes, firmware updates, and network administration tasks makes this vulnerability particularly dangerous, as exploitation could lead to widespread system compromise. This aligns with ATT&CK technique T1059.007 for command and scripting interpreter and T1071.004 for application layer protocol, as the vulnerability enables attackers to execute commands through the compromised TFTP service.
Mitigation strategies for CVE-2006-4948 should prioritize immediate remediation through software updates to the latest version of ProSysInfo TFTP Server or complete removal of the vulnerable software from network environments. Network segmentation and access controls should be implemented to limit exposure of TFTP services to trusted networks only, while firewall rules can be configured to restrict TFTP traffic to necessary sources. Additionally, implementing network monitoring solutions can help detect anomalous TFTP traffic patterns that might indicate exploitation attempts. The vulnerability demonstrates the critical importance of input validation and proper bounds checking in network services, reinforcing industry best practices for secure coding as outlined in OWASP Top Ten and NIST Cybersecurity Framework guidelines. Organizations should conduct comprehensive vulnerability assessments to identify all instances of this software and ensure complete remediation across their infrastructure.