VULNERABILITY INTELLIGENCE

CVE-2025-6442

CVSS score5.9 MEDIUM
EPSS probability0.50%
CISA KEVNot currently listed
Published2025-06-25
Last modified2026-06-17
CVSS vectorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N

Description

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. An attacker can leverage this vulnerability to smuggle arbitrary HTTP requests. Was ZDI-CAN-21876.

Weakness classification

  • CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')

Primary references