CVE-2017-3933 in McAfee Network Data Loss Prevention
Summary
by MITRE
Embedding Script (XSS) in HTTP Headers vulnerability in McAfee Network Data Loss Prevention (NDLP) 9.3.x allows remote authenticated users to view confidential information via a cross site request forgery attack.
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Analysis
by VulDB Data Team • 01/21/2021
The CVE-2017-3933 vulnerability represents a critical cross site scripting flaw within McAfee Network Data Loss Prevention version 9.3.x that specifically targets HTTP headers. This vulnerability arises from insufficient input validation and output sanitization mechanisms within the NDLP system's header processing functionality. The flaw enables authenticated attackers to inject malicious scripts into HTTP headers, which can then be executed in the context of a victim's browser when they interact with the affected system. The vulnerability specifically impacts the embedding of scripts within HTTP headers, creating a persistent XSS vector that can be exploited across multiple sessions and user interactions. This type of vulnerability falls under CWE-79 which categorizes cross site scripting flaws as a fundamental web application security weakness. The attack vector leverages the fact that HTTP headers are often processed and displayed within web interfaces without proper sanitization, allowing malicious payloads to persist and execute when legitimate users access the system.
The technical implementation of this vulnerability stems from the NDLP system's failure to properly validate and sanitize user-supplied data that gets embedded into HTTP headers. When authenticated users interact with the system, their input can be manipulated to include malicious script code that gets stored and later executed in the browser context of other users. This creates a sophisticated attack scenario where the malicious code can access session cookies, steal authentication tokens, and potentially exfiltrate sensitive data from the victim's browser session. The vulnerability specifically affects the header processing components that handle user input and display it within the web interface, creating a persistent threat that can affect multiple users over time. The authentication requirement for exploitation does not mitigate the severity since the attacker can leverage the authenticated session to inject malicious code that will execute against other legitimate users. This vulnerability aligns with ATT&CK technique T1059.001 which covers command and scripting interpreter usage, particularly in web application contexts where malicious scripts can be injected and executed.
The operational impact of CVE-2017-3933 extends beyond simple information disclosure to create significant security risks for organizations using McAfee NDLP systems. The vulnerability allows attackers to potentially escalate privileges, access confidential data, and perform unauthorized actions within the system's administrative interface. Since the attack requires only authentication, it can be particularly dangerous in environments where legitimate users maintain persistent sessions or where session management is weak. The persistent nature of the XSS vulnerability means that once exploited, the malicious code can continue to affect users until the system is patched or the injected payload is removed. Organizations may experience unauthorized access to sensitive network data, potential data exfiltration, and compromised user sessions. The vulnerability can also be leveraged to perform more sophisticated attacks such as session hijacking, credential theft, and privilege escalation within the NDLP environment. The impact is particularly severe given that NDLP systems are designed to protect against data loss and unauthorized access, making the exploitation of such vulnerabilities a direct contradiction to their intended security function.
Organizations affected by CVE-2017-3933 should immediately implement the vendor-provided security patches and updates to address the XSS vulnerability in McAfee Network Data Loss Prevention 9.3.x systems. The remediation process should include comprehensive testing of the patch in non-production environments before deployment to ensure compatibility with existing configurations. Network administrators should also implement additional monitoring and logging mechanisms to detect potential exploitation attempts, including monitoring for unusual header content or script injection patterns. Security teams should review and strengthen their session management policies, implement proper input validation for all HTTP headers, and establish more robust access controls for authenticated users. The vulnerability highlights the importance of regular security assessments and vulnerability scanning to identify similar issues in other network security appliances. Organizations should also consider implementing web application firewalls and additional security controls to provide defense in depth against similar cross site scripting attacks. The incident underscores the necessity of maintaining up-to-date security patches and following security best practices for network security tools to prevent exploitation of known vulnerabilities. Regular security training for administrators and developers is also recommended to ensure proper input validation and output encoding practices are implemented throughout the organization's security infrastructure.