ZTNA traffic interception via missing certificate hostname check
Published Oct 14, 2025 · Updated Oct 14, 2025
Improper certificate hostname validation in Fortinet FortiOS, FortiProxy, and FortiPAM allows man-in-the-middle attackers to alter ZTNA traffic. The ZTNA proxy accepts a peer certificate without verifying that its hostname matches the intended endpoint, allowing an impostor to terminate the TLS connection. Exploitation requires a position between the appliance and ZTNA proxy; intercepted connections can be read and modified, while other impacts are unreported.
Summary
What happened
Improper certificate hostname validation in Fortinet FortiOS, FortiProxy, and FortiPAM allows man-in-the-middle attackers to alter ZTNA traffic. The ZTNA proxy accepts a peer certificate without verifying that its hostname matches the intended endpoint, allowing an impostor to terminate the TLS connection. Exploitation requires a position between the appliance and ZTNA proxy; intercepted connections can be read and modified, while other impacts are unreported.
The record
- CVE
- CVE-2025-25253
- Published
- Oct 14, 2025
- Updated
- Oct 14, 2025
- Vendor
- Fortinet
- Product
- FortiOS
- Classifications
- CWE-297, T1557
- Attack vector
- adjacent
- Privileges
- unauthenticated
Timeline
How it unfolded
- Oct 14, 2025CVE publishedPublication date reported by the CVE source.
- Oct 14, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=7.0.0 <=7.0.17
- Affected versionversion=7.2.0 <=7.2.12
- Affected versionversion=7.4.0 <=7.4.8
- Affected versionversion=7.6.0 <=7.6.2
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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