CVE-2020-37122 Overview
CVE-2020-37122 is a stack-based buffer overflow vulnerability affecting SpotFTP-FTP Password Recover version 2.4.8. This denial of service vulnerability allows attackers to crash the application by generating a large buffer overflow through the registration code input field. The attack requires user interaction, as the victim must input a specially crafted text file containing an oversized string as a registration code.
Critical Impact
Successful exploitation causes application crash and denial of service, potentially disrupting legitimate password recovery operations and user workflows.
Affected Products
- SpotFTP-FTP Password Recover 2.4.8
Discovery Timeline
- 2026-02-07 - CVE CVE-2020-37122 published to NVD
- 2026-02-09 - Last updated in NVD database
Technical Details for CVE-2020-37122
Vulnerability Analysis
This vulnerability is classified as CWE-121 (Stack-based Buffer Overflow). The flaw exists in how SpotFTP-FTP Password Recover handles user-supplied input in the registration code field. When processing the registration code, the application fails to properly validate the length of the input data before copying it to a fixed-size stack buffer, resulting in a classic stack-based buffer overflow condition.
The attack requires local access and user interaction, as the attacker must convince a user to input a malicious text file or directly enter the oversized string. While the immediate impact is limited to denial of service (application crash), stack-based buffer overflows can potentially be leveraged for more severe attacks depending on exploit sophistication and system protections in place.
Root Cause
The root cause is improper input validation in the registration code processing routine. The application allocates a fixed-size buffer on the stack to store the registration code but does not implement adequate bounds checking before copying user-supplied data into this buffer. When input exceeds the expected buffer size (approximately 1000 characters or more), it overwrites adjacent stack memory, corrupting the stack frame and causing the application to crash.
Attack Vector
The attack vector is local, requiring the attacker to either have direct access to the system or convince a user to perform the malicious action. The exploitation process involves:
- Creating a text file containing approximately 1000 or more 'Z' characters (or any repeating character pattern)
- Opening SpotFTP-FTP Password Recover on the target system
- Navigating to the registration dialog
- Inputting the contents of the malicious text file as the registration code
- The application crashes when attempting to process the oversized input
The vulnerability does not require authentication or elevated privileges, but does require user interaction to trigger. For detailed technical information about exploitation, refer to the Exploit-DB #48132 entry.
Detection Methods for CVE-2020-37122
Indicators of Compromise
- Unexpected crashes of the SpotFTP.exe or related processes with stack overflow error codes
- Presence of large text files (containing repetitive character patterns) in system temporary directories or user download folders
- Windows Application Event Log entries indicating access violations or stack buffer overrun exceptions from the SpotFTP application
- Unusual user activity involving repeated attempts to register or enter license codes
Detection Strategies
- Monitor for application crash events specifically from SpotFTP-FTP Password Recover processes using Windows Event Forwarding
- Implement endpoint detection rules to alert on applications attempting to read unusually large clipboard contents or text files into input fields
- Deploy behavior-based monitoring to detect buffer overflow crash patterns characteristic of denial of service attacks
- Utilize SentinelOne's behavioral AI engine to identify anomalous application termination patterns
Monitoring Recommendations
- Enable Windows Error Reporting (WER) collection to capture crash dumps for forensic analysis
- Configure application whitelisting policies to control execution of vulnerable software versions
- Implement user awareness training to reduce likelihood of social engineering attacks that could deliver malicious registration files
- Monitor file system activity for creation of suspiciously large text files with repetitive content patterns
How to Mitigate CVE-2020-37122
Immediate Actions Required
- Discontinue use of SpotFTP-FTP Password Recover version 2.4.8 until a patched version is available
- Implement application control policies to block execution of the vulnerable software version
- Educate users about the risks of inputting untrusted registration codes or files from unknown sources
- Consider alternative FTP password recovery tools that do not exhibit this vulnerability
Patch Information
No vendor patch information is currently available for this vulnerability. Users should check the NSA Auditor Homepage and SpotFTP Overview page for any future security updates. The VulnCheck SpotFTP DoS Advisory may also provide updated remediation guidance.
Workarounds
- Remove or uninstall SpotFTP-FTP Password Recover 2.4.8 from systems where it is not essential
- Restrict access to the application using Group Policy or endpoint management solutions to only authorized users who understand the risk
- Implement Data Execution Prevention (DEP) and Address Space Layout Randomization (ASLR) at the system level to reduce exploitability of buffer overflow vulnerabilities
- Use application sandboxing to limit the impact of potential crashes on the broader system
# Windows Registry configuration to enable DEP for all applications
# Run as Administrator in Command Prompt
bcdedit /set nx AlwaysOn
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
