CVE-2006-2407 in freeFTPd
Summary
by MITRE
Stack-based buffer overflow in (1) WeOnlyDo wodSSHServer ActiveX Component 1.2.7 and 1.3.3 DEMO, as used in other products including (2) FreeSSHd 1.0.9 and (3) freeFTPd 1.0.10, allows remote attackers to execute arbitrary code via a long key exchange algorithm string.
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Analysis
by VulDB Data Team • 01/20/2025
The vulnerability described in CVE-2006-2407 represents a critical stack-based buffer overflow affecting multiple SSH server implementations that utilize the WeOnlyDo wodSSHServer ActiveX component. This flaw exists in versions 1.2.7 and 1.3.3 DEMO of the wodSSHServer component, which are integrated into popular open-source security tools including FreeSSHd 1.0.9 and freeFTPd 1.0.10. The vulnerability specifically manifests during the key exchange phase of SSH protocol communication, where an attacker can exploit the insufficient input validation to overwrite adjacent memory locations on the stack. The buffer overflow occurs when processing a specially crafted key exchange algorithm string that exceeds the allocated buffer size, potentially allowing remote code execution with the privileges of the affected service. This type of vulnerability falls under CWE-121 Stack-based Buffer Overflow, which is classified as a critical weakness in software security where data written to a buffer extends beyond the buffer's boundaries and overwrites adjacent memory locations. The operational impact of this vulnerability is severe as it enables remote attackers to execute arbitrary code on systems running vulnerable versions of these SSH implementations. Attackers can leverage this flaw to gain unauthorized access to systems, escalate privileges, and potentially establish persistent backdoors within network infrastructure. The vulnerability is particularly dangerous because it affects widely used open-source security tools that many organizations depend on for network services, creating a significant risk across multiple deployment scenarios. The attack vector requires only a remote connection to the vulnerable service, making exploitation relatively straightforward for attackers with network access. This vulnerability aligns with ATT&CK technique T1021.004 for Remote Services and T1059.007 for Command and Scripting Interpreter, as it allows for remote code execution through SSH services and can be used to establish command execution capabilities. The flaw demonstrates a classic lack of proper input sanitization and bounds checking in the SSH key exchange implementation, where the system fails to validate the length of the key exchange algorithm string before processing it. Organizations using these vulnerable products face significant risk of compromise, as the vulnerability can be exploited by attackers without requiring authentication for the exploitation phase, though valid SSH connections may still be necessary for the attack to succeed. The vulnerability is particularly concerning in enterprise environments where these tools are commonly deployed for remote access and file transfer services, making it a prime target for attackers seeking to gain unauthorized access to network infrastructure. System administrators should prioritize patching these vulnerable components as they represent a critical security risk that could lead to complete system compromise and unauthorized access to sensitive network resources. The remediation approach involves updating to patched versions of the affected software components, ensuring that proper input validation and buffer management practices are implemented in all SSH implementations, and conducting thorough security assessments of all systems running vulnerable versions of these tools.