CVE-2018-19953 in QTS
Summary
by MITRE • 10/29/2020
If exploited, this cross-site scripting vulnerability could allow remote attackers to inject malicious code. QNAP has already fixed the issue in the following QTS versions. QTS 4.4.2.1231 on build 20200302; QTS 4.4.1.1201 on build 20200130; QTS 4.3.6.1218 on build 20200214; QTS 4.3.4.1190 on build 20200107; QTS 4.3.3.1161 on build 20200109; QTS 4.2.6 on build 20200109.
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Analysis
by VulDB Data Team • 05/04/2025
This cross-site scripting vulnerability identified as CVE-2018-19953 represents a critical security flaw in QNAP QTS operating systems that enables remote attackers to execute malicious code through web interfaces. The vulnerability stems from inadequate input validation and output encoding mechanisms within the web application components of the QNAP QTS platform, creating an attack surface where user-supplied data is not properly sanitized before being rendered in web responses. Such weaknesses fall under the common weakness enumeration CWE-79 which specifically addresses cross-site scripting vulnerabilities where untrusted data is incorporated into web pages without proper validation or escaping mechanisms. The flaw allows attackers to inject malicious scripts that can execute in the context of a victim's browser session, potentially leading to unauthorized access to sensitive data, session hijacking, or further exploitation of the compromised system.
The operational impact of this vulnerability extends beyond simple script injection as it fundamentally compromises the integrity of the QNAP device's web interface security model. Attackers can leverage this flaw to manipulate web content, steal user credentials, access restricted administrative functions, or redirect users to malicious sites. The vulnerability affects multiple QNAP QTS versions including 4.4.2.1231, 4.4.1.1201, 4.3.6.1218, 4.3.4.1190, 4.3.3.1161, and 4.2.6, indicating a widespread issue across the QNAP product line that could affect numerous enterprise and home network storage devices. The exploitation of this vulnerability aligns with tactics described in the attack pattern framework where adversaries leverage web application flaws to establish persistent access to network resources, particularly relevant for storage appliances that often serve as critical infrastructure components. Organizations using affected QNAP devices face significant risk of data breaches, unauthorized access to network storage, and potential lateral movement within their network environments.
The remediation approach for this vulnerability requires immediate implementation of the patched QTS versions released by QNAP, with specific builds targeted for each affected version to ensure complete remediation. System administrators must prioritize updating all affected QNAP devices to the specified build versions, as these patches contain the necessary input validation improvements and output encoding fixes that prevent malicious script injection. The mitigation strategy should also include implementing additional security controls such as web application firewalls, network segmentation, and regular security assessments to detect potential exploitation attempts. Organizations should consider conducting vulnerability scans to identify any remaining unpatched devices within their network infrastructure and establish monitoring procedures to detect anomalous behavior that might indicate exploitation attempts. The vulnerability's classification under the attack framework highlights the importance of maintaining up-to-date security patches and implementing defense-in-depth strategies to protect against such web-based attack vectors that can compromise storage infrastructure and potentially lead to broader network compromises.