Description
An issue was discovered in Ruby through 2.5.8, 2.6.x through 2.6.6, and 2.7.x through 2.7.1. WEBrick, a simple HTTP server bundled with Ruby, had not checked the transfer-encoding header value rigorously. An attacker may potentially exploit this issue to bypass a reverse proxy (which also has a poor header check), which may lead to an HTTP Request Smuggling attack.
Remediation
References
Related Vulnerabilities
WordPress Plugin Work The Flow File Upload Arbitrary File Upload (2.5.2)
WordPress Plugin WordPress Book List Arbitrary File Upload (5.0.11)
WordPress Plugin InstaWP Connect-1-click WP Staging & Migration Security Bypass (0.1.0.38)
Joomla Improper Certificate Validation Vulnerability (CVE-2017-11364)