CVE-2006-7007 in Tiny FTPd
Summary
by MITRE
Buffer overflow in Tiny FTPd 1.4 and earlier allows remote attackers to cause a denial of service (daemon crash) via a long USER command, a different vector than CVE-2000-0133.
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Analysis
by VulDB Data Team • 06/24/2024
The vulnerability identified as CVE-2006-7007 represents a critical buffer overflow flaw within Tiny FTPd version 1.4 and earlier implementations. This security weakness specifically manifests when the ftp daemon processes an excessively long USER command, creating a condition where memory boundaries are exceeded during command handling. The flaw operates at the protocol level where the ftp server fails to properly validate input length before processing user authentication commands, leading to unauthorized memory corruption that fundamentally compromises system stability.
The technical execution of this vulnerability involves a classic stack-based buffer overflow scenario where malicious actors can craft USER commands containing excessive character sequences that exceed the allocated buffer space. When the ftp daemon attempts to process this oversized input, it writes beyond the intended memory boundaries, potentially overwriting adjacent memory locations including return addresses and control data. This overflow condition directly leads to daemon termination and system crash, effectively creating a denial of service condition that disrupts legitimate ftp service operations for all users.
From an operational perspective, this vulnerability presents significant risks to organizations relying on Tiny FTPd for file transfer services. The remote attack vector means that adversaries can exploit this weakness from any network location without requiring local system access or authentication credentials. The impact extends beyond simple service disruption as the daemon crash can potentially expose underlying system instability and may provide attackers with opportunities to escalate privileges or execute additional malicious payloads. The vulnerability's classification under CWE-121 indicates it falls within the category of stack-based buffer overflow conditions that represent one of the most common and dangerous software flaws in network services.
The attack surface for CVE-2006-7007 aligns with the ATT&CK framework's T1190 technique for exploitation of remote services, specifically targeting the ftp protocol service. Organizations implementing this vulnerable ftp daemon face potential compromise of their file transfer infrastructure, with attackers able to repeatedly exploit the flaw to maintain persistent service disruption. The vulnerability's relationship to CVE-2000-0133 demonstrates a pattern of similar buffer overflow issues in ftp implementations, highlighting the persistent nature of these flaws in network service applications. Security practitioners should note that this vulnerability's exploitation requires minimal technical expertise and can be automated, making it particularly dangerous in environments where ftp services are not properly monitored or patched.
Mitigation strategies for this vulnerability primarily focus on immediate software updates and patches provided by the Tiny FTPd developers. System administrators should prioritize upgrading to versions that address this specific buffer overflow condition, as the patch typically involves implementing proper input validation and bounds checking for user commands. Network-level defenses should include implementing firewall rules that limit ftp service access to trusted networks and monitoring for unusual USER command patterns that might indicate exploitation attempts. Additionally, implementing intrusion detection systems capable of identifying malformed ftp commands and deploying application-level firewalls that can filter out oversized USER commands provides layered protection against this specific vulnerability. The fundamental requirement for addressing this flaw involves comprehensive software maintenance procedures that ensure all network services are regularly updated to protect against known buffer overflow vulnerabilities that could otherwise provide attackers with complete system compromise capabilities.