CVE-2025-48865

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.

CVSS v3 9.1 CRITICAL

9.1^/10

CVSS v3 : CRITICAL

Vector :

Exploitability : 3.9 / Impact : 5.2

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://github.com/fabiolb/fabio/commit/fdaf1e966162e9dd3b347ffdd0647b39dc71a1a3	Patch
https://github.com/fabiolb/fabio/releases/tag/v1.6.6	Release Notes
https://github.com/fabiolb/fabio/security/advisories/GHSA-q7p4-7xjv-j3wf	Exploit Vendor Advisory
https://github.com/fabiolb/fabio/security/advisories/GHSA-q7p4-7xjv-j3wf	Exploit Vendor Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:fabiolb:fabio:*:*:*:*:*:go:*:*

History

04 Jun 2025, 19:54

Type	Values Removed	Values Added
New CVE

Information

Published : 2025-05-30 07:15

Updated : 2025-06-04 19:54

NVD link : CVE-2025-48865

Mitre link : CVE-2025-48865

CVE.ORG link : CVE-2025-48865

JSON object : View

Products Affected

fabiolb

fabio

CWE

CWE-345

Insufficient Verification of Data Authenticity

CWE-348

Use of Less Trusted Source

{"id": "CVE-2025-48865", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Secondary", "source": "security-advisories@github.com", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 9.1, "attackVector": "NETWORK", "baseSeverity": "CRITICAL", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}, "impactScore": 5.2, "exploitabilityScore": 3.9}, {"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 9.1, "attackVector": "NETWORK", "baseSeverity": "CRITICAL", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}, "impactScore": 5.2, "exploitabilityScore": 3.9}]}, "published": "2025-05-30T07:15:23.940", "references": [{"url": "https://github.com/fabiolb/fabio/commit/fdaf1e966162e9dd3b347ffdd0647b39dc71a1a3", "tags": ["Patch"], "source": "security-advisories@github.com"}, {"url": "https://github.com/fabiolb/fabio/releases/tag/v1.6.6", "tags": ["Release Notes"], "source": "security-advisories@github.com"}, {"url": "https://github.com/fabiolb/fabio/security/advisories/GHSA-q7p4-7xjv-j3wf", "tags": ["Exploit", "Vendor Advisory"], "source": "security-advisories@github.com"}, {"url": "https://github.com/fabiolb/fabio/security/advisories/GHSA-q7p4-7xjv-j3wf", "tags": ["Exploit", "Vendor Advisory"], "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Secondary", "source": "security-advisories@github.com", "description": [{"lang": "en", "value": "CWE-345"}, {"lang": "en", "value": "CWE-348"}]}, {"type": "Primary", "source": "nvd@nist.gov", "description": [{"lang": "en", "value": "CWE-345"}]}], "descriptions": [{"lang": "en", "value": "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."}, {"lang": "es", "value": "Fabio es un enrutador HTTP(S) y TCP para implementar aplicaciones administradas por consul. Antes de la versi\u00f3n 1.6.6, Fabio permit\u00eda a los clientes eliminar los encabezados X-Forwarded (excepto X-Forwarded-For) debido a una vulnerabilidad en el procesamiento de los encabezados salto a salto. Fabio a\u00f1ade encabezados HTTP como X-Forwarded-Host y X-Forwarded-Port al enrutar solicitudes a aplicaciones backend. Dado que la aplicaci\u00f3n receptora debe confiar en estos encabezados, permitir que los clientes HTTP los eliminen o modifiquen crea posibles vulnerabilidades de seguridad. Algunos de estos encabezados personalizados pueden eliminarse y, en ciertos casos, manipularse. El ataque se basa en que los encabezados pueden definirse como salto a salto mediante el encabezado HTTP Connection. Este problema se ha corregido en la versi\u00f3n 1.6.6."}], "lastModified": "2025-06-04T19:54:41.613", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:fabiolb:fabio:*:*:*:*:*:go:*:*", "vulnerable": true, "matchCriteriaId": "6A945EFC-B582-43E7-A382-9EE8DFF03511", "versionEndExcluding": "1.6.6"}], "operator": "OR"}]}], "sourceIdentifier": "security-advisories@github.com"}