CVE-2019-7876 in Magento
Summary
by MITRE
A remote code execution vulnerability exists in Magento 2.1 prior to 2.1.18, Magento 2.2 prior to 2.2.9, Magento 2.3 prior to 2.3.2. An authenticated user with privileges to manipulate layouts can insert a malicious payload into the layout.
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Analysis
by VulDB Data Team • 07/19/2020
This vulnerability represents a critical remote code execution flaw in the Magento e-commerce platform that affects multiple versions including Magento 2.1.x before 2.1.18, Magento 2.2.x before 2.2.9, and Magento 2.3.x before 2.3.2. The vulnerability stems from insufficient input validation and sanitization within the layout rendering mechanism, creating an avenue for malicious code injection. According to CWE-94, this falls under the category of "Improper Control of Generation of Code" where the application fails to properly control the generation or execution of code, allowing attackers to execute arbitrary commands on the affected system. The vulnerability is particularly dangerous because it requires only authenticated access with specific privileges to manipulate layouts, which many administrative users possess.
The technical flaw manifests when an authenticated user with layout modification privileges can inject malicious code into the layout files through the administrative interface. This occurs because the platform does not adequately sanitize or validate user-supplied input before incorporating it into the layout rendering process. Attackers can exploit this by crafting malicious payloads that get executed when the affected layout is rendered, potentially allowing full system compromise. The vulnerability operates at the application layer and can be classified under ATT&CK technique T1059.007 for "Command and Scripting Interpreter: PowerShell" and T1566.001 for "Phishing: Spearphishing Attachment" as attackers can leverage this to execute malicious code remotely. The attack chain typically involves gaining administrative access, manipulating layout files through the web interface, and then triggering the execution of malicious code when the modified layout is processed.
The operational impact of this vulnerability is severe for organizations using affected Magento versions, as it provides attackers with a pathway to achieve complete system compromise. Successful exploitation can result in data theft, system takeover, and potential lateral movement within the network infrastructure. Organizations may experience significant financial losses due to compromised customer data, regulatory fines, and business disruption. The vulnerability affects the integrity and confidentiality of the entire Magento installation, potentially exposing sensitive customer information and financial data. Security teams must understand that this vulnerability can be exploited by attackers with relatively low privileges within the administrative interface, making it particularly concerning for organizations with less stringent access controls. The attack surface extends beyond the immediate Magento installation to include any systems that may be compromised through the execution of malicious code.
Mitigation strategies should include immediate patching of all affected Magento versions to the latest available releases, which contain proper input validation and sanitization mechanisms. Organizations should implement strict access controls and principle of least privilege for administrative users, ensuring that only necessary personnel have layout modification privileges. Network segmentation and monitoring of administrative interfaces can help detect suspicious activities. Regular security audits and code reviews should focus on input validation mechanisms and layout rendering processes. Additionally, implementing web application firewalls and intrusion detection systems can provide additional layers of protection. According to NIST SP 800-53 controls, organizations should maintain updated vulnerability management processes and implement configuration management procedures to prevent unauthorized changes to critical system components. The remediation process should also include comprehensive testing of patches in staging environments before deployment to production systems to ensure no regressions occur.