CVE-2009-0288 in TFTPUtil
Summary
by MITRE
Directory traversal vulnerability in k23productions TFTPUtil GUI 1.2.0 and 1.3.0 allows remote attackers to read arbitrary files outside the TFTP root directory via directory traversal sequences in a GET request.
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Analysis
by VulDB Data Team • 08/04/2021
The directory traversal vulnerability identified as CVE-2009-0288 affects k23productions TFTPUtil GUI versions 1.2.0 and 1.3.0, representing a critical security flaw that enables remote attackers to access files beyond the intended TFTP root directory. This vulnerability stems from inadequate input validation within the TFTP client implementation, specifically when processing GET requests that contain directory traversal sequences such as ../ or ..\.. This flaw allows malicious actors to bypass normal file access restrictions and retrieve sensitive files from the underlying file system. The vulnerability is classified under CWE-22, which describes improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal attacks. Such attacks exploit insufficient validation of file paths to access files outside the designated directory structure, potentially exposing system configuration files, user data, or other sensitive resources.
The technical implementation of this vulnerability occurs within the TFTP client's handling of file retrieval operations, where the software fails to properly sanitize or validate the file paths provided in GET requests. When a remote attacker sends a specially crafted GET request containing directory traversal sequences, the TFTPUtil GUI processes these sequences without adequate restrictions, allowing access to files that should remain protected within the TFTP root directory. This flaw essentially creates a bypass mechanism that allows attackers to navigate the file system hierarchy and access arbitrary files, potentially including system configuration files, log files, or other sensitive data that should not be accessible through the TFTP service. The vulnerability is particularly dangerous because it can be exploited remotely without requiring authentication, making it an attractive target for attackers seeking to gather information about the target system or access sensitive data.
The operational impact of CVE-2009-0288 extends beyond simple unauthorized file access, as it can facilitate more sophisticated attacks within a compromised environment. Attackers can leverage this vulnerability to access system configuration files, user credentials, or other sensitive data that may be stored on the same system hosting the vulnerable TFTP service. The vulnerability can also serve as a reconnaissance tool, allowing attackers to map the file system structure and identify additional targets for exploitation. From an attacker's perspective, this vulnerability aligns with techniques described in the MITRE ATT&CK framework under the T1083 technique for discovering system information, and the T1566 technique for phishing with a malicious attachment, as it enables attackers to gather information that can be used for further exploitation. The ability to read arbitrary files outside the TFTP root directory can lead to information disclosure, privilege escalation, or even system compromise, depending on what files are accessible through this vulnerability.
Mitigation strategies for CVE-2009-0288 should focus on both immediate remediation and long-term security hardening measures. The most effective immediate solution involves upgrading to a patched version of k23productions TFTPUtil GUI that properly validates and sanitizes file paths in GET requests. Organizations should also implement network segmentation to limit access to TFTP services, ensuring that only authorized systems can communicate with the vulnerable service. Additional protective measures include implementing proper access controls, monitoring for suspicious TFTP traffic patterns, and conducting regular vulnerability assessments to identify similar flaws in other network services. Security professionals should also consider implementing network-based intrusion detection systems that can detect and alert on directory traversal attempts, as well as establishing proper file system permissions that limit access to sensitive files even if the vulnerability is exploited. The vulnerability demonstrates the importance of input validation and proper path handling in network applications, aligning with security best practices outlined in various cybersecurity frameworks including NIST SP 800-53 and ISO 27001. Organizations should also ensure that all network services undergo proper security testing, including penetration testing and code review, to identify and remediate similar vulnerabilities before they can be exploited by malicious actors.