CVE-2025-6442 – Ruby WEBrick read_header HTTP Request Smuggling Vulnerability

https://notcve.org/view.php?id=CVE-2025-6442

23 Jun 2025 — Ruby WEBrick read_header HTTP Request Smuggling Vulnerability. This vulnerability allows remote attackers to smuggle arbitrary HTTP requests on affected installations of Ruby WEBrick. This issue is exploitable when the product is deployed behind an HTTP proxy that fulfills specific conditions. The specific flaw exists within the read_headers method. The issue results from the inconsistent parsing of terminators of HTTP headers. • https://github.com/ruby/webrick/commit/ee60354bcb84ec33b9245e1d1aa6e1f7e8132101#diff-ad02984d873efb089aa51551bc6b7d307a53e0ba1ac439e91d69c2e58a478864 • CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') •