CVE-2019-25587 Overview
CVE-2019-25587 is a denial of service vulnerability affecting BulletProof FTP Server 2019.0.0.50. The vulnerability exists in the Storage-Path configuration parameter, which fails to properly validate the length of user-supplied input. Local attackers can exploit this flaw by enabling the Override Storage-Path setting and supplying an excessively long string value of 500 bytes or more, causing the application to crash when saving the configuration.
Critical Impact
Local attackers can cause a denial of service condition by crashing the BulletProof FTP Server application through a buffer overflow in the Storage-Path configuration parameter.
Affected Products
- BulletProof FTP Server version 2019.0.0.50
- Windows installations of BPFTP Server
Discovery Timeline
- 2026-03-22 - CVE CVE-2019-25587 published to NVD
- 2026-03-25 - Last updated in NVD database
Technical Details for CVE-2019-25587
Vulnerability Analysis
This vulnerability is classified under CWE-1282, which relates to assumed-immutable data being stored in writable memory. The core issue stems from improper input validation in the Storage-Path configuration handler within BulletProof FTP Server. When a user enables the Override Storage-Path setting and provides an exceptionally long string (500 bytes or more), the application fails to properly bounds-check the input before processing it.
The local attack vector requires an attacker to have access to the server's configuration interface. While this limits the attack surface compared to remote vulnerabilities, it still presents a significant risk in multi-user environments or scenarios where administrative access may be compromised.
Root Cause
The root cause of CVE-2019-25587 is inadequate input length validation in the Storage-Path configuration parameter handler. The application allocates a fixed-size buffer for storing the path value but does not enforce appropriate length restrictions on user input. When the configuration is saved with an oversized value, the buffer overflow condition triggers an application crash.
Attack Vector
The attack requires local access to the BulletProof FTP Server configuration interface. An attacker must:
- Access the server configuration settings
- Enable the Override Storage-Path option
- Paste a string buffer of 500 bytes or more into the Storage-Path field
- Trigger the configuration save operation
The exploitation is straightforward and does not require sophisticated techniques. Upon saving the malformed configuration, the application crashes, resulting in denial of service for all FTP server users.
The vulnerability mechanism involves improper handling of oversized input in the Storage-Path configuration field. When the Override Storage-Path setting is enabled and a buffer exceeding 500 bytes is supplied, the application fails to validate the input length before attempting to process and save the configuration. This results in a buffer overflow condition that crashes the application. Technical details and proof of concept information can be found in the Exploit-DB #46876 advisory.
Detection Methods for CVE-2019-25587
Indicators of Compromise
- Unexpected BulletProof FTP Server application crashes or service interruptions
- Configuration files containing abnormally long Storage-Path values exceeding 500 bytes
- Windows Event Log entries showing application crashes for the BPFTP Server process
- Multiple service restart attempts in system logs
Detection Strategies
- Monitor Windows Application Event Logs for BulletProof FTP Server crash events
- Implement file integrity monitoring on FTP server configuration files to detect unauthorized modifications
- Review access logs for the FTP server administrative interface for suspicious activity
- Deploy endpoint detection solutions capable of identifying application crash patterns
Monitoring Recommendations
- Configure alerts for BulletProof FTP Server service failures or restarts
- Implement logging for all configuration changes to the FTP server
- Monitor system resource utilization for anomalies that may indicate exploitation attempts
- Establish baseline behavior for the FTP server to identify deviations
How to Mitigate CVE-2019-25587
Immediate Actions Required
- Restrict local access to the BulletProof FTP Server configuration interface to trusted administrators only
- Implement least-privilege access controls for the server hosting BulletProof FTP Server
- Consider disabling the Override Storage-Path feature if not required for operations
- Monitor for updates from the vendor at the BPFTP Server Homepage
Patch Information
At the time of publication, no official patch information is available from the vendor. Organizations should monitor the BPFTP Server Windows Download page for updated versions that address this vulnerability. Review the VulnCheck Advisory on BPFTP for additional mitigation guidance.
Workarounds
- Implement strict access controls limiting who can access the FTP server configuration interface
- Disable the Override Storage-Path feature if it is not essential for operations
- Deploy application-level monitoring to detect and alert on configuration changes
- Consider migrating to an alternative FTP server solution if the vulnerability poses unacceptable risk
# Example: Restrict access to BulletProof FTP Server configuration directory
# Limit permissions to trusted administrator accounts only
icacls "C:\Program Files\BulletProof FTP Server" /inheritance:r
icacls "C:\Program Files\BulletProof FTP Server" /grant:r Administrators:F
icacls "C:\Program Files\BulletProof FTP Server" /deny Users:(OI)(CI)(F)
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
