CVE-2017-17933 in SurgeFTP
Summary
by MITRE
cgi/surgeftpmgr.cgi (aka the Web Manager interface on TCP port 7021 or 9021) in NetWin SurgeFTP version 23f2 has XSS via the classid, domainid, or username parameter.
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Analysis
by VulDB Data Team • 01/19/2023
The vulnerability identified as CVE-2017-17933 affects the NetWin SurgeFTP server version 23f2, specifically targeting its web-based management interface accessible through TCP ports 7021 or 9021. This issue represents a cross-site scripting vulnerability that allows remote attackers to inject malicious scripts into the web interface, potentially compromising the security of authenticated users who interact with the management console. The vulnerability is particularly concerning as it resides in the core administrative interface that system administrators use to manage FTP server configurations and user accounts. The affected parameters classid, domainid, and username are all processed without proper input validation or output encoding, creating opportunities for attackers to execute malicious code within the context of the victim's browser session. This type of vulnerability falls under CWE-79 which specifically addresses cross-site scripting flaws in web applications, making it a critical concern for web security.
The technical exploitation of this vulnerability occurs when an attacker crafts malicious input containing script code in any of the three vulnerable parameters during interaction with the web management interface. When the vulnerable parameters are processed and displayed within the web page without proper sanitization, the injected scripts execute in the browser context of authenticated users who access the affected interface. The impact extends beyond simple script execution as it can enable session hijacking, credential theft, and potentially full system compromise if administrators interact with malicious content. The attack vector is remote and requires no authentication to the FTP service itself, though access to the web management interface is necessary for exploitation. This vulnerability demonstrates poor input validation practices and highlights the importance of implementing proper output encoding for all user-controllable data displayed in web interfaces, which aligns with defensive techniques recommended in the ATT&CK framework under the execution and credential access phases.
The operational impact of this vulnerability is significant for organizations using NetWin SurgeFTP version 23f2, as it creates a potential entry point for attackers to escalate privileges and gain unauthorized access to the FTP server management functions. System administrators who regularly use the web interface become targets for social engineering attacks where they might unknowingly execute malicious scripts that could redirect them to phishing sites or steal their authentication tokens. The vulnerability affects the integrity and confidentiality of the administrative interface, potentially allowing attackers to modify user accounts, change server configurations, or even gain access to sensitive system information. Organizations relying on this FTP server implementation face increased risk of unauthorized access, data breaches, and potential lateral movement within their network infrastructure. The vulnerability also impacts the availability of the service if attackers exploit it to manipulate server configurations or create denial of service conditions through malformed parameter inputs, making it a critical issue that requires immediate remediation.
Organizations should implement immediate mitigations including applying the vendor-provided security patch for NetWin SurgeFTP version 23f2, which addresses the input validation flaws in the affected CGI scripts. Network segmentation and access control measures should be implemented to restrict access to the web management interface to trusted administrative networks only, reducing the attack surface. Additionally, implementing proper input validation and output encoding mechanisms in all web applications, including the use of Content Security Policy headers, can help prevent script execution in the browser context. Regular security assessments and penetration testing should be conducted to identify similar vulnerabilities in other web applications and interfaces. System administrators should be trained to recognize potential phishing attempts and avoid interacting with suspicious web content, particularly when using administrative interfaces. The vulnerability also underscores the importance of maintaining updated security controls and following secure coding practices to prevent similar issues in future development cycles, as recommended by industry standards and best practices for web application security.