GHSA-8j7c-682x-r9f2: 
PHP vulnerability analysis and mitigation

Magento Commerce and Open Source versions 2.1 (prior to 2.1.16) and 2.2 (prior to 2.2.7) contain multiple critical security vulnerabilities including Remote Code Execution (RCE), Cross-Site Scripting (XSS), and other security issues. This security update was released on November 28, 2018, with patches available in versions 2.1.16, 2.2.7, and 2.3.0 (Magento Security).

The vulnerabilities include multiple high-severity issues with CVSSv3 scores ranging from 9.1 to 4.2. The most critical vulnerabilities include PHP Object Injection (POI) and Remote Code Execution (RCE) in the Admin interface with a CVSSv3 score of 9.1, unauthorized file upload vulnerabilities through customer attributes with a CVSSv3 score of 9.0, and multiple RCE vulnerabilities through path traversal with CVSSv3 scores of 8.8 and above (Magento Security).

The vulnerabilities could allow attackers to execute remote code, perform unauthorized file uploads, escalate privileges, and conduct cross-site scripting attacks. The most severe impacts include potential remote code execution through various attack vectors, unauthorized access to system files, and compromise of administrator accounts (Magento Security).

The vulnerabilities were addressed in Magento versions 2.1.16, 2.2.7, and 2.3.0. Users are advised to upgrade to these patched versions. For those unable to upgrade immediately, it is recommended to follow Magento's Security Best Practices and implement proper access controls (Magento Security).