CVE-2001-1042 in Broker FTP Server
Summary
by MITRE
Transsoft Broker 5.9.5.0 allows remote attackers to read arbitrary files and directories by uploading a .lnk (link) file that points to the target file.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 05/22/2019
The vulnerability identified as CVE-2001-1042 represents a critical security flaw in Transsoft Broker version 5.9.5.0 that enables remote attackers to access arbitrary files and directories through a specifically crafted file upload mechanism. This vulnerability operates through a sophisticated attack vector that exploits the software's handling of symbolic link files, particularly those with the .lnk extension that are commonly associated with Windows operating systems. The flaw exists in the file processing logic where the application fails to properly validate or sanitize file paths contained within link files, creating an opportunity for path traversal attacks that can bypass normal access controls.
The technical implementation of this vulnerability stems from the software's insufficient input validation and inadequate file path resolution mechanisms. When a malicious user uploads a .lnk file containing a crafted target path, the Transsoft Broker application processes this link without proper sanitization of the target file path. This allows attackers to construct malicious link files that point to sensitive system files or directories outside the intended upload location. The vulnerability specifically leverages the Windows shortcut file format's ability to reference arbitrary file paths, enabling attackers to navigate the file system beyond the boundaries of the application's intended access scope. This represents a classic path traversal vulnerability that can be categorized under CWE-22, which describes improper limitation of a pathname to a restricted directory.
The operational impact of this vulnerability extends far beyond simple unauthorized file access, as it provides attackers with the capability to extract sensitive information from the targeted system. An attacker could potentially access configuration files, database credentials, system logs, or other critical data that should remain protected within the application's designated boundaries. The remote nature of the attack means that exploitation does not require physical access to the system, making it particularly dangerous for networked environments where the application might be exposed to untrusted users. This vulnerability creates a persistent threat vector that can be exploited repeatedly, allowing attackers to gather intelligence about the target system and potentially escalate their access privileges.
The security implications of CVE-2001-1042 align with several techniques documented in the MITRE ATT&CK framework, particularly those related to credential access and privilege escalation. Attackers can leverage this vulnerability to obtain sensitive information that may include database connection strings, application configuration details, or system credentials stored in accessible files. The attack pattern follows the methodology described in ATT&CK technique T1005, which covers data from local system, and T1078, which covers valid accounts. Organizations using Transsoft Broker 5.9.5.0 should implement immediate mitigations including input validation, file type restrictions, and proper path sanitization to prevent the exploitation of this vulnerability. The remediation process should involve updating to a patched version of the software, implementing network segmentation to limit access to the application, and conducting comprehensive security assessments to identify any potential compromise from prior exploitation attempts.