CVE-2023-0887 in TFTPD64-SE
Summary
by MITRE • 02/17/2023
A vulnerability was found in phjounin TFTPD64-SE 4.64 and classified as critical. This issue affects some unknown processing of the file tftpd64_svc.exe. The manipulation leads to unquoted search path. An attack has to be approached locally. The associated identifier of this vulnerability is VDB-221351.
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Analysis
by VulDB Data Team • 03/18/2023
The vulnerability identified as CVE-2023-0887 represents a critical security flaw in phjounin TFTPD64-SE version 4.64, specifically within the tftpd64_svc.exe component. This issue falls under the category of unquoted search path vulnerabilities, which occur when Windows service executables are installed without proper quotation marks around their paths. The vulnerability is classified as critical due to its potential for privilege escalation and arbitrary code execution, making it a significant concern for system administrators and security professionals. The flaw exists in the service installation process where the path to tftpd64_svc.exe contains spaces but lacks proper quotation, creating an exploitable condition that can be leveraged by local attackers to execute malicious code with elevated privileges.
The technical exploitation of this vulnerability stems from Windows service behavior where the operating system searches for executables in the specified path using a specific search order. When a service path contains spaces but is not quoted, Windows interprets the path as multiple separate components, potentially allowing an attacker to place malicious executables in directories that are searched before the legitimate service executable. This behavior aligns with CWE-428, which describes the weakness of unquoted search paths in Windows environments. The vulnerability specifically affects the tftpd64_svc.exe file, which is part of the TFTPD64-SE network service implementation, making it a legitimate target for exploitation in environments where this service is deployed.
The operational impact of CVE-2023-0887 is particularly concerning as it requires only local access to exploit, meaning that an attacker with physical or network access to a system running the vulnerable service can potentially gain elevated privileges. This vulnerability can lead to complete system compromise, allowing attackers to execute arbitrary code with system-level privileges, escalate their access, and potentially establish persistent backdoors. The attack vector being local in nature means that network-based exploitation is not required, reducing the complexity of the attack and increasing the likelihood of successful compromise. This aligns with ATT&CK technique T1068, which covers local privilege escalation through service misconfigurations, and demonstrates how seemingly minor installation flaws can have significant security implications.
Mitigation strategies for CVE-2023-0887 should focus on immediate remediation through proper service installation procedures that ensure all paths containing spaces are properly quoted. System administrators should verify that the tftpd64_svc.exe service is installed with proper quotation marks around its path, preventing the search path vulnerability from being exploited. Additionally, implementing the principle of least privilege and ensuring that the service runs with minimal required permissions can reduce the potential impact of successful exploitation. Regular security audits should be conducted to identify other services that may be vulnerable to similar path traversal issues, and organizations should consider implementing application whitelisting policies to prevent unauthorized executables from running on systems. The vulnerability also highlights the importance of proper software installation practices and the need for regular updates to address known security issues in third-party applications.