CVE-2020-37063 in TFTP Turbo
Summary
by MITRE • 02/01/2026
TFTP Turbo 4.6.1273 contains an unquoted service path vulnerability that allows local attackers to potentially execute arbitrary code with elevated privileges. Attackers can exploit the unquoted path in the service configuration to inject malicious executables that will be launched with LocalSystem permissions.
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Analysis
by VulDB Data Team • 02/02/2026
The vulnerability identified as CVE-2020-37063 affects TFTP Turbo version 4.6.1273 and represents a critical security flaw stemming from an unquoted service path configuration. This issue resides within the Windows service installation where the executable path contains spaces but lacks proper quotation marks around the full path specification. The root cause aligns with CWE-428, which addresses the improper handling of unquoted service paths in Windows environments. When Windows attempts to launch the service, it interprets the path segments as separate executable components, creating opportunities for privilege escalation attacks.
The technical exploitation of this vulnerability occurs when an attacker places a malicious executable file in a directory that appears before the legitimate service path in the Windows search order. Since the service runs with LocalSystem privileges, any code executed through this vector gains the highest level of system permissions available to Windows services. The unquoted path vulnerability specifically enables attackers to manipulate the service execution flow by injecting their malicious payload at a location that Windows will traverse during service startup. This flaw operates under the ATT&CK framework category of privilege escalation through service misconfiguration, specifically targeting T1543.003 which covers Create or Modify System Process.
The operational impact of this vulnerability extends beyond simple code execution as it provides attackers with persistent access to the compromised system with elevated privileges. Local attackers who can write to directories in the service path can place malicious executables that will be executed with system-level permissions, effectively allowing them to establish backdoors, escalate privileges, or perform other malicious activities that require administrative access. The vulnerability is particularly concerning because it does not require network connectivity or complex exploitation techniques, making it accessible to attackers with basic local system access. The service configuration allows for arbitrary code execution through path manipulation, which aligns with the principle of least privilege violations and represents a significant security weakness in the application's installation process.
Mitigation strategies for CVE-2020-37063 should focus on proper service path configuration and system hardening measures. The primary recommendation involves reconfiguring the service installation to use properly quoted paths that prevent Windows from interpreting intermediate directory names as executable components. System administrators should verify all service paths are enclosed in double quotation marks to ensure proper execution context. Additionally, implementing the principle of least privilege through restricted user access and proper file system permissions can limit the effectiveness of potential exploitation attempts. Regular vulnerability scanning and service path validation should be part of routine security maintenance procedures to identify and remediate similar configuration issues across the enterprise. Organizations should also consider implementing application whitelisting policies and monitoring for suspicious service execution patterns to detect potential exploitation attempts. The remediation process should include updating to patched versions of TFTP Turbo where available, as this vulnerability specifically relates to improper service installation practices that have been addressed in subsequent releases of the software.