Ruby WEBrick HTTP Request read_header request smuggling

CVSS Meta Temp Score
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CTI Interest Score
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5.3$0-$5k0.00

Summaryinfo

A vulnerability was found in Ruby WEBrick and classified as problematic. The affected element is the function read_header of the component HTTP Request Handler. Executing a manipulation can lead to request smuggling. This vulnerability is registered as CVE-2025-6442. It is possible to launch the attack remotely. No exploit is available. It is advisable to implement a patch to correct this issue.

Detailsinfo

A vulnerability classified as problematic was found in Ruby WEBrick (the affected version is unknown). This vulnerability affects the function read_header of the component HTTP Request Handler. The manipulation with an unknown input leads to a request smuggling vulnerability. The CWE definition for the vulnerability is CWE-444. The product acts as an intermediary HTTP agent (such as a proxy or firewall) in the data flow between two entities such as a client and server, but it does not interpret malformed HTTP requests or responses in ways that are consistent with how the messages will be processed by those entities that are at the ultimate destination. As an impact it is known to affect integrity. CVE summarizes:

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.

The advisory is shared for download at zerodayinitiative.com. This vulnerability was named CVE-2025-6442 since 06/20/2025. The exploitation appears to be difficult. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. There are known technical details, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 241924 (CBL Mariner 2.0 Security Update: ruby / rubygem-webrick (CVE-2025-6442)), which helps to determine the existence of the flaw in a target environment.

Applying the patch ee60354bcb84ec33b9245e1d1aa6e1f7e8132101 is able to eliminate this problem. The bugfix is ready for download at github.com.

The vulnerability is also documented in the databases at Tenable (241924), EUVD (EUVD-2025-19113) and CERT Bund (WID-SEC-2025-2475). Once again VulDB remains the best source for vulnerability data.

Affected

  • Apple macOS

Productinfo

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Vendor

Name

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.4
VulDB Meta Temp Score: 5.3

VulDB Base Score: 3.7
VulDB Temp Score: 3.6
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 5.9
NVD Vector: 🔒

CNA Base Score: 6.5
CNA Vector: 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Request smuggling
CWE: CWE-444
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 241924
Nessus Name: CBL Mariner 2.0 Security Update: ruby / rubygem-webrick (CVE-2025-6442)

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Patch
Status: 🔍

0-Day Time: 🔒

Patch: ee60354bcb84ec33b9245e1d1aa6e1f7e8132101

Timelineinfo

06/20/2025 CVE reserved
06/23/2025 +3 days Advisory disclosed
06/23/2025 +0 days VulDB entry created
11/15/2025 +145 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: zerodayinitiative.com
Status: Confirmed

CVE: CVE-2025-6442 (🔒)
GCVE (CVE): GCVE-0-2025-6442
GCVE (VulDB): GCVE-100-313660
EUVD: 🔒
CERT Bund: WID-SEC-2025-2475 - Apple macOS: Mehrere Schwachstellen

Entryinfo

Created: 06/23/2025 16:43
Updated: 11/15/2025 14:31
Changes: 06/23/2025 16:43 (54), 06/25/2025 22:46 (1), 06/26/2025 03:57 (12), 07/11/2025 15:44 (2), 08/18/2025 19:19 (12), 11/15/2025 14:31 (7)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

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