CVE-2019-8137 in Magento
Summary
by MITRE
A remote code execution vulnerability exists in Magento 2.2 prior to 2.2.10, Magento 2.3 prior to 2.3.3 or 2.3.2-p1. An authenticated user with privileges to manipulate CMS section of the website can trigger remote code execution via custom layout update.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 02/04/2024
The vulnerability identified as CVE-2019-8137 represents a critical remote code execution flaw affecting Magento e-commerce platforms. This security weakness impacts versions prior to specific patches including Magento 2.2 before 2.2.10, Magento 2.3 before 2.3.3, and 2.3.2-p1. The vulnerability stems from insufficient input validation and sanitization within the CMS section of the platform, creating a pathway for malicious actors to execute arbitrary code on affected systems. The flaw specifically manifests when authenticated users with appropriate privileges manipulate custom layout updates within the CMS functionality, exploiting a lack of proper security controls in the content management workflow.
The technical implementation of this vulnerability involves a dangerous interaction between user input and the platform's layout rendering system. When an authenticated user with CMS privileges creates or modifies custom layout updates, the system fails to adequately validate or sanitize the input data before processing. This insufficient validation allows malicious payloads to be embedded within layout update parameters, which are then executed during the rendering process. The vulnerability operates at the intersection of input validation failure and privilege escalation, where legitimate administrative access becomes a vector for code execution. According to CWE classification, this represents a weakness categorized under CWE-20: Improper Input Validation, specifically manifesting as CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component.
The operational impact of CVE-2019-8137 extends beyond simple remote code execution to encompass complete system compromise and data breach potential. An attacker with access to a CMS user account can leverage this vulnerability to execute malicious code with the privileges of the web application, potentially leading to full system takeover. The attack surface is particularly concerning because it requires only authenticated access to the CMS section, which is often accessible to users with varying levels of administrative privileges. This vulnerability can be exploited to install backdoors, steal sensitive customer data, modify product information, or redirect traffic to malicious sites. The attack chain typically involves gaining initial access through a compromised CMS user account, crafting malicious layout updates, and then executing the payload through the platform's rendering engine.
Security practitioners should implement immediate mitigations focusing on access control and input validation. The primary recommendation involves applying the vendor-provided patches for Magento versions 2.2.10, 2.3.3, and 2.3.2-p1 respectively. Additionally, organizations should enforce strict access controls limiting CMS privileges to only essential personnel and implement comprehensive monitoring of layout update activities. The vulnerability aligns with ATT&CK technique T1059.001 for command and scripting interpreter, and T1078.004 for valid accounts, demonstrating how legitimate administrative access can be abused for malicious purposes. Network segmentation and Web Application Firewall rules can provide additional defense-in-depth measures, while regular security assessments should verify that no unauthorized modifications have occurred. The vulnerability also highlights the importance of principle of least privilege in e-commerce environments where CMS access is often granted more broadly than necessary, creating potential attack vectors for sophisticated adversaries.