CVE-2007-6378 in BadBlue
Summary
by MITRE
Directory traversal vulnerability in upload.dll in BadBlue 2.72b and earlier allows remote attackers to create or overwrite arbitrary files via a .. (dot dot) in the filename parameter.
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Analysis
by VulDB Data Team • 09/13/2018
The vulnerability identified as CVE-2007-6378 represents a critical directory traversal flaw within the BadBlue web server software version 2.72b and earlier. This issue resides in the upload.dll component which handles file upload operations, creating a pathway for remote attackers to manipulate the file system through carefully crafted requests. The vulnerability stems from inadequate input validation mechanisms that fail to properly sanitize filename parameters containing directory traversal sequences.
The technical exploitation of this vulnerability occurs when an attacker submits a filename parameter containing .. (dot dot) sequences that manipulate the intended file destination path. This allows the malicious user to navigate outside the designated upload directory and create or overwrite files in arbitrary locations on the server filesystem. The flaw essentially bypasses normal file access controls and directory restrictions, enabling attackers to place malicious files in critical system directories or overwrite existing legitimate files with harmful content.
From an operational impact perspective, this vulnerability presents a severe security risk as it can be exploited remotely without authentication requirements. Attackers can leverage this weakness to upload malicious files such as web shells, backdoors, or other harmful executables that can compromise the entire server. The ability to overwrite existing files could lead to service disruption, data corruption, or the complete compromise of the web server infrastructure. This vulnerability directly maps to CWE-22, which describes improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal attacks.
The exploitation of CVE-2007-6378 aligns with several tactics outlined in the MITRE ATT&CK framework, particularly those related to initial access and execution phases. Attackers can use this vulnerability to establish persistent access through web shell uploads, which would then be categorized under the execution tactic. The vulnerability also enables privilege escalation scenarios when attackers can overwrite system-critical files or configuration files that are later executed by the web server process.
Effective mitigation strategies for this vulnerability include immediate patching of the BadBlue software to versions that properly validate and sanitize filename parameters. System administrators should implement proper input validation at multiple layers including web application firewalls, server-side validation, and directory access controls. Network segmentation and restricted file upload permissions can help limit the impact even if exploitation occurs. Additionally, monitoring for unusual file creation patterns and implementing regular security audits of web server configurations can help detect potential exploitation attempts. The vulnerability demonstrates the critical importance of proper input validation and the principle of least privilege in web application security design, aligning with security best practices outlined in OWASP Top Ten and NIST cybersecurity frameworks.