CVE-2025-6442 Details
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.
A request smuggling vulnerability has been identified in Ruby WEBrick, allowing remote attackers to send arbitrary HTTP requests. This issue arises from inconsistent parsing of HTTP header terminators in the 'read_headers' method, creating a flaw that can be exploited when WEBrick is behind a specific type of HTTP proxy.
Ruby has released a patch for this vulnerability. Users should update to the latest version of WEBrick.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed Jun 25, 2025References to Advisories, Solutions, and Tools
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Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-444 | Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| ruby-lang webrick | < 1.8.2 |
CPE
Remediation
| |
Change History
4 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| Aug 18, 2025 | Initial Analysis | [email protected] |
| Jun 25, 2025 | New CVE Received | [email protected] |