CVE-2010-4154 in FTP Voyager
Summary
by MITRE
Directory traversal vulnerability in Rhino Software, Inc. FTP Voyager 15.2.0.11, and possibly earlier, allows remote FTP servers to write arbitrary files via a "..\" (dot dot backslash) in a filename.
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Analysis
by VulDB Data Team • 01/05/2018
The vulnerability identified as CVE-2010-4154 represents a critical directory traversal flaw within Rhino Software, Inc. FTP Voyager version 15.2.0.11 and potentially earlier releases. This security weakness stems from inadequate input validation mechanisms within the FTP client software, specifically when processing filenames containing malicious directory traversal sequences. The flaw manifests when the application fails to properly sanitize or validate filenames that contain "..\" sequences, which are commonly used in directory traversal attacks to navigate outside of intended directories. Such vulnerabilities fall under the CWE-22 category, which specifically addresses improper limitation of a pathname to a restricted directory, also known as path traversal or directory traversal. The attack vector involves a remote FTP server that can manipulate file names during transfer operations, exploiting the client-side software's insufficient validation routines to write files to arbitrary locations on the victim's system.
The technical implementation of this vulnerability exploits the fundamental design flaw in how FTP Voyager processes filenames containing backslash sequences. When a remote server sends a filename with "..\" characters, the client application interprets these sequences as commands to traverse parent directories, bypassing normal file system access controls. This behavior creates a scenario where an attacker-controlled remote server can instruct the vulnerable client to write files anywhere within the local file system, potentially overwriting critical system files or creating malicious executables. The vulnerability specifically affects the file name parsing logic within the FTP client, where the software does not properly validate or sanitize the path components of filenames before attempting to write them to disk. This weakness aligns with ATT&CK technique T1059.007 for Command and Scripting Interpreter: PowerShell, as the vulnerability enables arbitrary file creation that could be leveraged to establish persistence or execute malicious code.
The operational impact of CVE-2010-4154 extends beyond simple unauthorized file creation, as it provides attackers with the capability to potentially compromise the entire system through strategic file placement. An attacker could exploit this vulnerability to overwrite system binaries, install backdoors, or create malicious scripts that execute with the privileges of the user running FTP Voyager. The severity is amplified by the fact that this vulnerability affects a widely used FTP client application, making it a prime target for exploitation in various attack scenarios. The attack requires minimal privileges from the remote server side, as it only needs to send a specially crafted filename during an FTP transfer operation. This vulnerability can be particularly dangerous in environments where users frequently connect to untrusted FTP servers, as the exploitation can occur without user interaction or awareness. The flaw essentially allows for arbitrary file system manipulation, which can lead to complete system compromise, data exfiltration, or the establishment of persistent access points. Organizations using FTP Voyager versions affected by this vulnerability should consider immediate mitigation strategies, including software updates, network segmentation, and user education about the risks of connecting to untrusted FTP servers. The vulnerability's classification under CWE-22 and its potential for privilege escalation make it a critical concern for enterprise security teams, as it represents a fundamental breakdown in file system access control mechanisms within the client application.