Fabio is an HTTP(S) and TCP router for deploying applications managed by consul. Prior to version 1.6.6, Fabio allows clients to remove X-Forwarded headers (except X-Forwarded-For) due to a vulnerability in how it processes hop-by-hop headers. Fabio adds HTTP headers like X-Forwarded-Host and X-Forwarded-Port when routing requests to backend applications. Since the receiving application should trust these headers, allowing HTTP clients to remove or modify them creates potential security vulnerabilities. Some of these custom headers can be removed and, in certain cases, manipulated. The attack relies on the behavior that headers can be defined as hop-by-hop via the HTTP Connection header. This issue has been patched in version 1.6.6.
History

Wed, 04 Jun 2025 20:15:00 +0000

Type Values Removed Values Added
First Time appeared Fabiolb
Fabiolb fabio
CPEs cpe:2.3:a:fabiolb:fabio:*:*:*:*:*:go:*:*
Vendors & Products Fabiolb
Fabiolb fabio

Fri, 30 May 2025 13:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Fri, 30 May 2025 06:30:00 +0000

Type Values Removed Values Added
Description Fabio is an HTTP(S) and TCP router for deploying applications managed by consul. Prior to version 1.6.6, Fabio allows clients to remove X-Forwarded headers (except X-Forwarded-For) due to a vulnerability in how it processes hop-by-hop headers. Fabio adds HTTP headers like X-Forwarded-Host and X-Forwarded-Port when routing requests to backend applications. Since the receiving application should trust these headers, allowing HTTP clients to remove or modify them creates potential security vulnerabilities. Some of these custom headers can be removed and, in certain cases, manipulated. The attack relies on the behavior that headers can be defined as hop-by-hop via the HTTP Connection header. This issue has been patched in version 1.6.6.
Title Fabio allows HTTP clients to manipulate custom headers it adds
Weaknesses CWE-345
CWE-348
References
Metrics cvssV3_1

{'score': 9.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2025-05-30T06:14:45.819Z

Updated: 2025-05-30T12:24:19.086Z

Reserved: 2025-05-27T20:14:34.294Z

Link: CVE-2025-48865

cve-icon Vulnrichment

Updated: 2025-05-30T12:24:03.593Z

cve-icon NVD

Status : Analyzed

Published: 2025-05-30T07:15:23.940

Modified: 2025-06-04T19:54:41.613

Link: CVE-2025-48865

cve-icon Redhat

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