CVE-2010-3100 in FTP Client
Summary
by MITRE
Directory traversal vulnerability in Porta+ FTP Client 4.1, and possibly other versions, allows remote FTP servers to overwrite arbitrary files via a directory traversal sequences in a filename.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 01/07/2018
The CVE-2010-3100 vulnerability represents a critical directory traversal flaw in Porta+ FTP Client version 4.1 and potentially other iterations, exposing users to significant security risks through remote exploitation. This vulnerability specifically targets the client-side file handling mechanisms within the FTP application, creating a pathway for malicious FTP servers to manipulate local file systems. The flaw arises from inadequate input validation and path resolution processes that fail to properly sanitize filenames containing traversal sequences such as ../ or ..\, which are commonly used to navigate file system directories. When a user connects to a compromised FTP server and downloads files with maliciously crafted names, the client processes these filenames without sufficient safeguards, allowing attackers to specify arbitrary file paths that can overwrite existing system files or create new files in sensitive locations.
The technical implementation of this vulnerability demonstrates a classic path traversal attack vector that operates at the application layer of network communications. The flaw occurs during the file download process when the FTP client receives a filename containing directory traversal sequences from the remote server. The client's file system operations do not properly validate or sanitize these filenames before attempting to write files to the local system, creating a condition where attacker-controlled paths can be resolved relative to the intended download directory. This type of vulnerability maps directly to CWE-22, which defines improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal. The vulnerability is particularly dangerous because it can be exploited through legitimate FTP connections, making it difficult for users to detect malicious activity. The attack requires minimal privileges on the FTP server side, as the malicious behavior is executed through normal FTP protocol operations rather than requiring elevated permissions.
The operational impact of CVE-2010-3100 extends beyond simple file overwrites to encompass potential system compromise and data exfiltration scenarios. An attacker who successfully exploits this vulnerability can overwrite critical system files, configuration files, or user data, potentially leading to system instability, privilege escalation, or complete system compromise. The vulnerability can be leveraged to overwrite executable files, which could result in code execution when the system attempts to run these modified programs. Additionally, attackers may use this flaw to create backdoor files or modify existing system components to maintain persistent access to compromised systems. The attack can be automated through malicious FTP servers that are configured to deliver payloads containing traversal sequences, making it particularly dangerous in environments where users frequently connect to untrusted FTP services. This vulnerability aligns with several tactics described in the MITRE ATT&CK framework under the T1078 technique for valid accounts and T1059 for command and scripting interpreter, as it allows for the execution of malicious payloads through legitimate network protocols.
Mitigation strategies for CVE-2010-3100 should focus on both immediate remediation and long-term security enhancements. The most effective immediate solution involves updating to a patched version of Porta+ FTP Client that properly validates and sanitizes filenames during FTP operations, ensuring that directory traversal sequences are either rejected or properly resolved within safe boundaries. Organizations should implement network segmentation and access controls to limit FTP client connectivity to trusted servers, reducing the attack surface available to potential exploit attempts. Security monitoring should include detection of unusual file system activity, particularly around the download directories of FTP clients, to identify potential exploitation attempts. Additionally, users should be educated about the risks of connecting to untrusted FTP servers and the importance of verifying server authenticity before establishing connections. Network administrators should consider implementing firewall rules that restrict FTP traffic to known good servers and monitor for suspicious file operations. The vulnerability also highlights the importance of input validation in client-side applications, reinforcing the need for proper security practices in software development. Organizations should establish regular vulnerability assessment procedures to identify similar flaws in other client applications and ensure that security patches are applied promptly to prevent exploitation.