CVE-2025-25255: Domain fronting protection bypass in explicit web proxy
An Improperly Implemented Security Check for Standard vulnerability [CWE-358] in FortiOS and FortiProxy explicit web proxy may allow an unauthenticated proxy user to bypass the domain fronting protection feature via crafted HTTP requests.
Other sources
An Improperly Implemented Security Check for Standard vulnerability [CWE-358] vulnerability in Fortinet FortiOS 7.6.0 through 7.6.3, FortiProxy 7.6.0 through 7.6.3, FortiProxy 7.4.0 through 7.4.11, FortiProxy 7.2 all versions, FortiProxy 7.0.1 through 7.0.22 may allow an unauthenticated proxy user to bypass the domain fronting protection feature via crafted HTTP requests.
— MITRE
Affected Software
Remediation
Information
Event History
Frequently Asked Questions
What is the severity of CVE-2025-25255?
CVE-2025-25255 is classified as a high severity vulnerability due to its potential to allow authenticated users to bypass domain fronting protections.
How do I fix CVE-2025-25255?
To remediate CVE-2025-25255, upgrade to FortiOS or FortiProxy version 7.6.4 or later.
Which products are affected by CVE-2025-25255?
CVE-2025-25255 affects FortiOS and FortiProxy versions between 7.0.1 and 7.6.3.
What type of vulnerability is CVE-2025-25255?
CVE-2025-25255 is an Improperly Implemented Security Check for Standard vulnerability that can be exploited through crafted HTTP requests.
Is there a security patch available for CVE-2025-25255?
Yes, Fortinet has released a security patch in version 7.6.4 to address CVE-2025-25255.