CVEvulnerability

CVE-2025-48865

9.1 CRITICAL Published 2025-05-30 Modified 2026-06-17 Official page ↗
Status
Analyzed
Published
2025-05-30
Last modified
2026-06-17
Assigner
[email protected]
CVSS 3.1 ([email protected])
9.1 CRITICAL — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
CVSS 3.1 ([email protected])
9.1 CRITICAL — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Weaknesses
CWE-345, CWE-348

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.

Affected configurations

• fabiolb fabio (< 1.6.6)

Related

Weakness · CWE (2)

  • CWE-345 Insufficient Verification of Data Authenticity weakness
  • CWE-348 Use of Less Trusted Source weakness

References