Fabio up to 1.6.5 Header data authenticity

CVSS Meta Temp Score
CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.
Current Exploit Price (≈)
Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.
CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
8.0$0-$5k0.00

Summaryinfo

A vulnerability was found in Fabio up to 1.6.5. It has been rated as critical. The affected element is an unknown function of the component Header Handler. Performing a manipulation results in data authenticity. This vulnerability is cataloged as CVE-2025-48865. It is possible to initiate the attack remotely. There is no exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Fabio up to 1.6.5. It has been classified as critical. This affects an unknown function of the component Header Handler. The manipulation with an unknown input leads to a data authenticity vulnerability. CWE is classifying the issue as CWE-345. The product does not sufficiently verify the origin or authenticity of data, in a way that causes it to accept invalid data. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

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.

The advisory is shared at github.com. This vulnerability is uniquely identified as CVE-2025-48865 since 05/27/2025. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Neither technical details nor an exploit are publicly available.

Upgrading to version 1.6.6 eliminates this vulnerability.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Name

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.2
VulDB Meta Temp Score: 8.0

VulDB Base Score: 7.3
VulDB Temp Score: 7.0
VulDB Vector: 🔍
VulDB Reliability: 🔍

CNA Base Score: 9.1
CNA Vector: 🔍

CVSSv2info

AVACAuCIA
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock

VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

Exploitinginfo

Class: Data authenticity
CWE: CWE-345
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-DayUnlockUnlockUnlockUnlock
TodayUnlockUnlockUnlockUnlock

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: Fabio 1.6.6

Timelineinfo

05/27/2025 🔍
05/29/2025 +2 days 🔍
05/29/2025 +0 days 🔍
05/30/2025 +1 days 🔍

Sourcesinfo

Advisory: github.com
Status: Confirmed

CVE: CVE-2025-48865 (🔍)
GCVE (CVE): GCVE-0-2025-48865
GCVE (VulDB): GCVE-100-310569

Entryinfo

Created: 05/29/2025 21:16
Updated: 05/30/2025 11:53
Changes: 05/29/2025 21:16 (51), 05/30/2025 11:53 (12)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Discussion

No comments yet. Languages: en.

Please log in to comment.

◂ PreviousOverviewNext ▸

Want to know what is going to be exploited?

We predict KEV entries!