CVE-2009-0753 in MLDonkey
Summary
by MITRE
Absolute path traversal vulnerability in MLDonkey 2.8.4 through 2.9.7 allows remote attackers to read arbitrary files via a leading "//" (double slash) in the filename.
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Analysis
by VulDB Data Team • 04/27/2025
The CVE-2009-0753 vulnerability represents a critical absolute path traversal flaw discovered in MLDonkey versions 2.8.4 through 2.9.7, exposing systems to unauthorized file access through carefully crafted network requests. This vulnerability specifically targets the file handling mechanisms within the MLDonkey peer-to-peer file sharing software, which is widely used for distributed file sharing across various networks. The flaw manifests when the application processes filenames containing a leading double slash sequence, allowing attackers to manipulate the file system path resolution mechanism. This particular vulnerability falls under the CWE-22 category of Path Traversal attacks, which is classified as a fundamental weakness in software security design that enables attackers to access files and directories outside of the intended scope.
The technical exploitation of this vulnerability occurs through the manipulation of filename parameters in network requests sent to the MLDonkey server. When a malicious user submits a request containing a filename that begins with double slashes, the application fails to properly sanitize or validate the input before processing it as a file path. This improper input validation allows the attacker to bypass normal path restrictions and traverse the file system to access sensitive files that should otherwise be protected. The vulnerability is particularly dangerous because it leverages the inherent behavior of Unix-like operating systems where double slashes in file paths are interpreted as the root directory, effectively allowing attackers to access files anywhere on the system regardless of the intended file access controls. This flaw directly relates to ATT&CK technique T1083, which focuses on discovering file and directory permissions on compromised systems, and T1566, which covers credential access through various attack vectors.
The operational impact of this vulnerability extends beyond simple unauthorized file access, creating significant risks for organizations relying on MLDonkey for file sharing operations. Attackers can exploit this flaw to access system configuration files, user credentials stored in various formats, application logs, and potentially sensitive data repositories that may be stored on the same system. The vulnerability affects not only the MLDonkey software itself but also the broader network infrastructure, as compromised systems can serve as entry points for further lateral movement within the network. Organizations using MLDonkey in production environments face potential data breaches, system compromise, and regulatory compliance violations, particularly in industries subject to strict data protection regulations. The vulnerability's remote nature means that attackers do not require physical access to the system, making it an attractive target for cybercriminals seeking to exploit network services without detection.
Mitigation strategies for CVE-2009-0753 should focus on immediate software updates to versions that address the path traversal vulnerability, as well as implementing network-level restrictions and input validation controls. System administrators should ensure that all MLDonkey installations are updated to versions that properly sanitize filename inputs and implement proper path validation mechanisms. Network segmentation and firewall rules should be implemented to restrict access to MLDonkey services, particularly in environments where the software is not essential for business operations. Additionally, organizations should conduct thorough security assessments to identify any systems running vulnerable versions of MLDonkey and implement monitoring solutions to detect suspicious file access patterns. The vulnerability underscores the importance of proper input validation and secure coding practices, particularly in network services that handle user-provided data. Organizations should also consider implementing principle of least privilege access controls and regular security audits to prevent similar vulnerabilities from being exploited in other software components. This vulnerability serves as a reminder of the critical importance of maintaining up-to-date software and implementing comprehensive security measures to protect against path traversal attacks that can compromise entire systems.