CVE-2019-12769 in Serv-U Managed File Transfer
Summary
by MITRE
SolarWinds Serv-U Managed File Transfer (MFT) Web client before 15.1.6 Hotfix 2 is vulnerable to Cross-Site Request Forgery in the file upload functionality via ?Command=Upload with the Dir and File parameters.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 05/12/2025
The vulnerability identified as CVE-2019-12769 affects SolarWinds Serv-U Managed File Transfer (MFT) Web client versions prior to 15.1.6 Hotfix 2, representing a critical cross-site request forgery flaw that specifically targets the file upload functionality. This vulnerability exists within the web interface's handling of the Command=Upload parameter, which processes file uploads through the Dir and File parameters, creating a dangerous attack surface that can be exploited by malicious actors to perform unauthorized file operations on vulnerable systems. The flaw stems from insufficient validation and authorization checks within the web client's request processing logic, allowing attackers to craft malicious requests that could execute file upload operations without proper user consent or authentication.
The technical exploitation of this CSRF vulnerability occurs when an authenticated user visits a malicious website or clicks on a crafted link that contains a hidden form or script designed to submit a file upload request to the vulnerable Serv-U MFT web interface. The attack leverages the fact that the web client does not properly validate the origin of requests or verify that the request was genuinely initiated by the authenticated user, making it possible for attackers to manipulate the Dir and File parameters to upload malicious files to targeted directories within the file transfer system. This represents a classic CSRF attack pattern where the attacker exploits the user's existing authenticated session to perform actions they would not normally be authorized to execute.
The operational impact of this vulnerability extends beyond simple unauthorized file uploads, as it can potentially enable attackers to gain persistent access to the file transfer environment and establish a foothold for further exploitation. Successful exploitation allows adversaries to upload malware, backdoor files, or other malicious content that could be used to compromise the underlying infrastructure, exfiltrate sensitive data, or establish command and control channels. The vulnerability is particularly concerning in enterprise environments where Serv-U MFT systems often handle sensitive corporate data and are integrated with critical business processes, making the potential for data breaches and system compromise significant. According to CWE classification, this vulnerability maps to CWE-352, which specifically addresses Cross-Site Request Forgery weaknesses in web applications.
Mitigation strategies for this vulnerability should include immediate deployment of the available patches and updates from SolarWinds, specifically the 15.1.6 Hotfix 2 release that addresses this CSRF flaw. Organizations should also implement additional security controls such as web application firewalls that can detect and block suspicious CSRF patterns, enforce strict origin validation on web requests, and implement additional authentication layers for file upload operations. Network segmentation and access controls should be reviewed to limit the potential impact of successful exploitation, while security monitoring should be enhanced to detect unusual file upload patterns or unauthorized access attempts. The ATT&CK framework categorizes this vulnerability under T1190 - Exploit Public-Facing Application, highlighting the importance of securing externally accessible web interfaces and implementing proper input validation and request origin verification mechanisms to prevent such attacks from succeeding.