Executive Summary

Title Fortigate UTM appliances share the same default CA certificate
Name VU#111708 First vendor Publication 2012-11-02
Vendor VU-CERT Last vendor Modification 2012-11-02
Severity (Vendor) N/A Revision M

Security-Database Scoring CVSS v3

Cvss vector : N/A
Overall CVSS Score NA
Base Score NA Environmental Score NA
impact SubScore NA Temporal Score NA
Exploitabality Sub Score NA
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Security-Database Scoring CVSS v2

Cvss vector : (AV:N/AC:M/Au:N/C:P/I:P/A:N)
Cvss Base Score 5.8 Attack Range Network
Cvss Impact Score 4.9 Attack Complexity Medium
Cvss Expoit Score 8.6 Authentication None Required
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Vulnerability Note VU#111708

Fortigate UTM appliances share the same default CA certificate

Original Release date: 02 Nov 2012 | Last revised: 02 Nov 2012


Fortigate UTM appliances that support SSL/TLS deep packet inspection share the same self-signed Fortigate CA certificate and associated private key across all devices. The private key, which has been compromised, allows attackers to create and sign fake certificates.


Fortigate UTM appliances share the same self-signed Fortigate CA certificate. Companies that use these appliances for deep packet inspection will have most likely deployed the CA certificate to endpoint web browsers so certificate warnings will not be seen by an end-user. Since the associated private key has been compromised (published on the web), an attacker with a man-in-the-middle vantage point on the network will be able to simulate the behavior of the Fortigate appliance and eavesdrop on encrypted communications or spoof websites. Also, the attacker may digitally sign malicious software, spoofing the identity of the publisher.


Primarily at risk are users who have imported the compromised Fortigate CA certificate into their web browser or operating system. This risk applies equally within the company (connected to a network behind the Fortigate UTM appliance) as anywhere else. An attacker with a man-in-the-middle vantage point on the current network may be able to eavesdrop on encrypted communications. In addition, an attacker may falsify digital signatures such as Authenticode.


Install a new CA certificate

The vendor recommends the following steps be taken to address this vulnerability.

  1. Admin creates/obtains a CA certificate for which only they have the private key.
  2. Admin installs the CA certificate on FortiGate.
  3. Admin uses "set caname xxx" to select that certificate for SSL deep inspection.
Disable the Fortigate CA certificate

Endpoints should not trust the self-signed Fortigate CA certificate. The following certificate information is for the certificate that should be distrusted:

Subject: "E = support@fortinet.com; CN = FortiGate CA; OU = Certificate Authority; O = Fortinet; L = Sunnyvale; S = California; C = US";
Thumbprint: 3e 20 7f 9a 6b d9 5c 7c 2b 89 11 67 d3 2f 57 87 2f 76 60 14

The preferrable way to distrust a CA certificate is to import it to the "Untrusted certificates" branch of the system certificate store. To continue the use of SSL/TLS deep packet inspection, a new, unique, CA certificate may be generated and imported into the Fortigate UTM appliance. To prevent users from experiencing certificate errors, that new CA certificate can be imported into web browsers. Chapter 6 of the FortiOS handbook contains instructions on how to replace the default CA certificate.

Vendor Information (Learn More)

VendorStatusDate NotifiedDate Updated
Fortinet, Inc.Affected07 Sep 201230 Oct 2012
If you are a vendor and your product is affected, let us know.

CVSS Metrics (Learn More)



  • http://docs.fortinet.com/fos40hlp/43/wwhelp/wwhimpl/common/html/wwhelp.htm?context=fgt&file=misc_utm_chapter.61.13.html
  • http://kb.fortinet.com/kb/viewContent.do?externalId=FD32404
  • http://www.fortinet.com/solutions/unified_threat_management.html
  • https://media.torproject.org/misc/2012-07-03-cyberoam-CVE-2012-3372.txt
  • http://docs.fortinet.com/fos40hlp/43/wwhelp/wwhimpl/js/html/wwhelp.htm


Thanks to Bitwiper for reporting this vulnerability.

This document was written by Jared Allar.

Other Information

  • CVE IDs:CVE-2012-4948
  • Date Public:22 Oct 2012
  • Date First Published:02 Nov 2012
  • Date Last Updated:02 Nov 2012
  • Document Revision:19


If you have feedback, comments, or additional information about this vulnerability, please send us email.

Original Source

Url : http://www.kb.cert.org/vuls/id/111708

CWE : Common Weakness Enumeration

% Id Name
50 % CWE-310 Cryptographic Issues
50 % CWE-295 Certificate Issues

CPE : Common Platform Enumeration

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Nessus® Vulnerability Scanner

Date Description
2012-11-19 Name : The SSL certificate for this service was signed by a certificate authority (C...
File : ssl_fortigate.nasl - Type : ACT_GATHER_INFO
2012-08-07 Name : The SSL certificate for this service was signed by a CA whose private key is ...
File : ssl_cyberoam.nasl - Type : ACT_GATHER_INFO

Alert History

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Date Informations
2014-02-17 12:07:30
  • Multiple Updates
2012-11-29 21:21:46
  • Multiple Updates
2012-11-29 21:20:28
  • Multiple Updates
2012-11-14 17:22:17
  • Multiple Updates