CVE-2017-5228 in Metasploit Framework
Summary
by MITRE
All editions of Rapid7 Metasploit prior to version 4.13.0-2017020701 contain a directory traversal vulnerability in the Meterpreter stdapi Dir.download() function. By using a specially-crafted build of Meterpreter, it is possible to write to an arbitrary directory on the Metasploit console with the permissions of the running Metasploit instance.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 06/21/2020
The vulnerability identified as CVE-2017-5228 represents a critical directory traversal flaw within the Rapid7 Metasploit framework that affects all editions prior to version 4.13.0-2017020701. This weakness specifically resides within the Meterpreter stdapi Dir.download() function, which serves as a core component for file operations within the post-exploitation framework. The vulnerability stems from inadequate input validation and path manipulation controls that allow malicious actors to exploit the function's handling of file paths during download operations. The flaw enables attackers to bypass normal file system access controls and write files to arbitrary locations on the host system where Metasploit is running.
The technical exploitation of this vulnerability occurs through the construction of specially crafted Meterpreter payloads that manipulate the download function's parameter handling. When an attacker successfully triggers this vulnerability, the Meterpreter module fails to properly sanitize or validate the destination path specified during file download operations. This allows the attacker to specify absolute paths or manipulate relative paths to traverse directories and write files outside of the intended download locations. The vulnerability operates at the file system level, leveraging the permissions of the running Metasploit process to perform write operations to directories that should normally be restricted.
The operational impact of CVE-2017-5228 extends beyond simple file system manipulation, as it provides attackers with potential persistence mechanisms and privilege escalation opportunities. Since the vulnerability allows writing to arbitrary directories with the permissions of the running Metasploit instance, an attacker could potentially place malicious executables, configuration files, or backdoors in system directories. This capability significantly increases the attack surface and could enable adversaries to maintain access to compromised systems even after initial exploitation. The vulnerability also affects the integrity of the Metasploit console environment, as unauthorized file modifications could compromise the tool's functionality or provide attackers with additional attack vectors.
From a cybersecurity framework perspective, this vulnerability aligns with CWE-22 Directory Traversal and maps to multiple ATT&CK techniques including T1059 Command and Scripting Interpreter and T1070 Indicator Removal on Host. The flaw demonstrates the importance of proper input validation and the principle of least privilege in security tool design. Organizations using Metasploit should immediately update to version 4.13.0-2017020701 or later to mitigate this risk. Additional mitigations include implementing network segmentation to limit access to Metasploit instances, monitoring for unusual file creation patterns, and conducting regular security assessments of penetration testing tools. The vulnerability also highlights the need for proper code review processes and security testing of post-exploitation frameworks to prevent similar issues in other security tools.