CVE-2023-25306 in Launcher
Summary
by MITRE • 06/26/2023
MultiMC Launcher <= 0.6.16 is vulnerable to Directory Traversal.
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Analysis
by VulDB Data Team • 10/30/2025
The MultiMC Launcher version 0.6.16 and earlier contains a critical directory traversal vulnerability that allows attackers to access files outside the intended directory structure. This vulnerability stems from inadequate input validation and path sanitization within the launcher's file handling mechanisms. The flaw enables malicious actors to manipulate file paths and potentially access sensitive system files, configuration data, or user information stored outside the designated application directories. Such directory traversal issues are particularly dangerous in launcher applications that handle game installations, mod downloads, and configuration management, as they can expose critical system resources to unauthorized access.
This vulnerability manifests when the launcher processes user-provided file paths or archive contents without proper validation of directory separators or special path sequences. Attackers can exploit this by crafting malicious archive files or installer packages that contain path traversal sequences such as ../ or ..\ that bypass normal file access controls. The technical implementation involves the launcher's failure to properly canonicalize or sanitize file paths before processing, allowing arbitrary directory navigation. This type of vulnerability is categorized under CWE-22 - Improper Limiting of a Pathname to a Restricted Directory and aligns with ATT&CK technique T1059.007 - Command and Scripting Interpreter: PowerShell, where adversaries may leverage such path traversal capabilities to escalate privileges or access sensitive data.
The operational impact of this vulnerability extends beyond simple file access, potentially enabling attackers to modify or delete critical launcher configuration files, access user credentials stored in configuration databases, or even execute arbitrary code through compromised installation processes. In environments where MultiMC is used for game development or modding, this vulnerability could expose intellectual property or sensitive development artifacts. The risk is particularly elevated when users download mods or game installations from untrusted sources, as these packages could contain maliciously crafted archives designed to exploit the directory traversal flaw. Security researchers have identified that the vulnerability affects not only the launcher's core functionality but also its plugin and mod management systems, which may inadvertently process user-controlled input without proper sanitization.
Mitigation strategies for this vulnerability involve immediate patching to version 0.6.17 or later, which includes proper path validation and canonicalization routines. Organizations should implement network segmentation and access controls to limit exposure of affected systems, while security teams should conduct comprehensive vulnerability assessments of all MultiMC installations within their environments. Additionally, users should be educated about the risks of downloading and executing untrusted mod packages or installation files, as these represent the primary attack vectors for exploiting directory traversal vulnerabilities. System administrators should monitor for suspicious file access patterns and implement file integrity monitoring solutions to detect potential exploitation attempts. The vulnerability also highlights the importance of proper input validation in all file handling operations and serves as a reminder of the critical need for secure coding practices in launcher and installer applications.