CVE-2019-11519 in nopCommerce
Summary
by MITRE
Libraries/Nop.Services/Localization/LocalizationService.cs in nopCommerce through 4.10 allows XXE via the "Configurations -> Languages -> Edit Language -> Import Resources -> Upload XML file" screen.
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Analysis
by VulDB Data Team • 09/07/2023
The vulnerability identified as CVE-2019-11519 affects nopCommerce versions through 4.10 and represents a critical XML External Entity injection flaw within the localization service component. This vulnerability exists in the Libraries/Nop.Services/Localization/LocalizationService.cs file and specifically impacts the administrative interface where users can import language resources through XML file uploads. The attack vector occurs through the configuration management section where administrators can edit language settings and import resource files, creating an opportunity for malicious actors to exploit the XML parsing functionality without proper input validation or sanitization.
The technical flaw stems from insufficient validation of XML input during the resource import process, allowing attackers to craft malicious XML files that contain external entity references. When the system processes these files, it fails to properly sanitize the XML content, enabling XML parsers to resolve external references and potentially access local files, perform server-side request forgery attacks, or execute arbitrary code depending on the underlying XML parser implementation. This vulnerability directly maps to CWE-611, which addresses Improper Restriction of XML External Entity Reference, and represents a classic XXE attack scenario that has been documented extensively in security literature and exploited in numerous production environments.
The operational impact of this vulnerability is significant for organizations using affected nopCommerce versions, as it provides attackers with potential access to sensitive system information and resources. Successful exploitation could allow adversaries to read local files on the server, potentially accessing configuration files, database credentials, or other sensitive data stored on the system. The vulnerability is particularly dangerous because it operates through the legitimate administrative upload functionality, making it difficult to detect through standard network monitoring. Attackers could leverage this weakness to escalate privileges, gain persistent access to the system, or use the compromised server as a pivot point for further attacks within the network infrastructure, aligning with ATT&CK technique T1059 for execution through XML files and T1566 for initial access via web applications.
Organizations should immediately implement multiple layers of mitigation to address this vulnerability. The primary defense involves updating to nopCommerce version 4.11 or later, which contains the necessary patches to prevent XXE attacks through proper XML input validation. Additionally, administrators should disable or restrict the language import functionality for untrusted users, implement proper XML parser configurations that disable external entity resolution, and conduct thorough input validation on all uploaded files. Network-based mitigations include implementing web application firewalls that can detect and block XXE patterns, while application-level protections should enforce strict XML schema validation and sanitize all external entity references. Organizations should also perform regular security assessments of their web applications, including XML parsing components, and establish proper access controls to limit administrative privileges to only trusted personnel. The vulnerability highlights the importance of input validation and secure coding practices, particularly when handling user-supplied data through XML processing components, and serves as a reminder of the critical need for regular security updates and vulnerability management processes.