CVE-2006-0100 in NicoFTP
Summary
by MITRE
Buffer overflow in NicoFTP 3.0.1.19 and earlier might allow local users to execute arbitrary code via a long string in the "Name of site" field of an FTP account. NOTE: because this program executes with the privileges of the invoking user, and because remote programs do not normally have the ability to create or modify FTP accounts in this program, there may not be a typical attack vector for the issue that crosses privilege boundaries. Therefore this may not be a vulnerability.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 07/17/2018
The vulnerability described in CVE-2006-0100 represents a classic buffer overflow flaw within NicoFTP version 3.0.1.19 and earlier installations. This type of vulnerability falls under CWE-121, which specifically addresses stack-based buffer overflow conditions where insufficient bounds checking allows attackers to overwrite adjacent memory locations. The flaw manifests when the application processes user input in the "Name of site" field of FTP account configurations, creating an exploitable condition that could potentially lead to arbitrary code execution within the context of the currently logged-in user.
The technical implementation of this vulnerability stems from inadequate input validation mechanisms within the NicoFTP application's account management subsystem. When users enter excessively long strings into the site name field, the application fails to properly enforce length restrictions on the buffer allocated to store this data. This lack of proper bounds checking allows the overflow to occur, potentially overwriting critical memory segments including return addresses, function pointers, or other control data structures that govern program execution flow. The buffer overflow creates a scenario where malicious input can manipulate the program's execution path and potentially inject or redirect code execution.
From an operational perspective, the impact of this vulnerability is constrained by the privilege model of the application itself. Since NicoFTP executes with the privileges of the invoking user rather than elevated administrative rights, the attack vector is limited to local execution scenarios where an attacker already has access to the system. This characteristic significantly reduces the potential attack surface compared to vulnerabilities that can be exploited remotely or across privilege boundaries. The vulnerability does not typically constitute a cross-privilege boundary issue as noted in the CVE description, since remote exploitation would be extremely difficult given that FTP account creation and modification normally requires local user interaction. However, the local execution potential still presents a security risk, particularly in environments where users might be tricked into creating maliciously crafted FTP site entries.
The mitigation strategies for this vulnerability primarily focus on input validation and application hardening measures. System administrators should immediately upgrade to NicoFTP versions that address this buffer overflow issue, as the original version is no longer supported and likely contains multiple unpatched security flaws. Additionally, implementing proper bounds checking and input sanitization within the application code would prevent the overflow condition from occurring. Security best practices recommend that all user inputs be validated against expected formats and length constraints, with defensive programming techniques such as stack canaries or address space layout randomization potentially providing additional protection layers. This vulnerability aligns with ATT&CK technique T1068 which covers exploiting vulnerabilities in legitimate programs, and demonstrates the importance of maintaining current software versions to avoid known security flaws. Organizations should also consider implementing application whitelisting policies to prevent execution of unpatched versions and establish monitoring procedures to detect potential exploitation attempts targeting known buffer overflow vulnerabilities in legacy applications.