Description
In WordPress 4.9.7, plugins uploaded via the admin area are not verified as being ZIP files. This allows for PHP files to be uploaded. Once a PHP file is uploaded, the plugin extraction fails, but the PHP file remains in a predictable wp-content/uploads location, allowing for an attacker to then execute the file. This represents a security risk in limited scenarios where an attacker (who does have the required capabilities for plugin uploads) cannot simply place arbitrary PHP code into a valid plugin ZIP file and upload that plugin, because a machine's wp-content/plugins directory permissions were set up to block all new plugins.
Remediation
References
Related Vulnerabilities
Oracle HTTP Server Other Vulnerability (CVE-2006-5350)
Oracle HTTP Server Out-of-bounds Read Vulnerability (CVE-2019-3823)
WordPress Plugin WP PHP widget Information Disclosure (1.0.2)
Joomla Improper Input Validation Vulnerability (CVE-2020-35616)
WordPress Plugin WP-Live Chat by 3CX Cross-Site Scripting (8.0.17)