CVE-2012-4948 - Improper Certificate Validation

Severity

53%

Complexity

32%

Confidentiality

130%

The default configuration of Fortinet Fortigate UTM appliances uses the same Certification Authority certificate and same private key across different customers' installations, which makes it easier for man-in-the-middle attackers to spoof SSL servers by leveraging the presence of the Fortinet_CA_SSLProxy certificate in a list of trusted root certification authorities.

The default configuration of Fortinet Fortigate UTM appliances uses the same Certification Authority certificate and same private key across different customers' installations, which makes it easier for man-in-the-middle attackers to spoof SSL servers by leveraging the presence of the Fortinet_CA_SSLProxy certificate in a list of trusted root certification authorities.

CVSS 2.0 Base Score 5.3. CVSS Attack Vector: adjacent_network. CVSS Attack Complexity: high. CVSS Vector: (AV:A/AC:H/Au:N/C:C/I:P/A:N).

Demo Examples

Improper Certificate Validation

CWE-295

This code checks the certificate of a connected peer.


               
foo=SSL_get_verify_result(ssl);
// certificate looks good, host can be trusted

In this case, because the certificate is self-signed, there was no external authority that could prove the identity of the host. The program could be communicating with a different system that is spoofing the host, e.g. by poisoning the DNS cache or using a MITM attack to modify the traffic from server to client.

Improper Certificate Validation

CWE-295

The following OpenSSL code obtains a certificate and verifies it.


               
}
// do secret things

Even though the "verify" step returns X509_V_OK, this step does not include checking the Common Name against the name of the host. That is, there is no guarantee that the certificate is for the desired host. The SSL connection could have been established with a malicious host that provided a valid certificate.

Improper Certificate Validation

CWE-295

The following OpenSSL code ensures that there is a certificate and allows the use of expired certificates.


               
//do stuff

If the call to SSL_get_verify_result() returns X509_V_ERR_CERT_HAS_EXPIRED, this means that the certificate has expired. As time goes on, there is an increasing chance for attackers to compromise the certificate.

Improper Certificate Validation

CWE-295

The following OpenSSL code ensures that there is a certificate before continuing execution.


               
// got a certificate, do secret things

Because this code does not use SSL_get_verify_results() to check the certificate, it could accept certificates that have been revoked (X509_V_ERR_CERT_REVOKED). The software could be communicating with a malicious host.

Improper Certificate Validation

CWE-295

The following OpenSSL code ensures that the host has a certificate.


               
}
// got certificate, host can be trusted//foo=SSL_get_verify_result(ssl);//if (X509_V_OK==foo) ...

Note that the code does not call SSL_get_verify_result(ssl), which effectively disables the validation step that checks the certificate.

Overview

Type

Fortinet

First reported 12 years ago

2012-11-14 12:30:00

Last updated 8 years ago

2016-12-07 18:14:00

Affected Software

Fortinet FortiGate-1000C

Fortinet FortiGate-100D

Fortinet FortiGate-110C

Fortinet FortiGate-1240B

Fortinet FortiGate-200B

Fortinet FortiGate-20C

Fortinet FortiGate-300C

Fortinet FortiGate-3040B

Fortinet FortiGate-310B

Fortinet FortiGate-311B

Fortinet FortiGate-3140B

Fortinet FortiGate-3240C

Fortinet FortiGate-3810A

Fortinet FortiGate-3950B

Fortinet FortiGate-40C

Fortinet Fortigate 5001A-SW

Fortinet Fortigate 5001B

Fortinet FortiGate-5020

Fortinet FortiGate-5060

Fortinet FortiGate-50B

Fortinet FortiGate-5101C

Fortinet FortiGate-5140b

Fortinet FortiGate-600C

Fortinet FortiGate-60C

Fortinet FortiGate-620B

Fortinet FortiGate-800C

Fortinet FortiGate-80C

Fortinet FortiGate-Voice-80C

Fortinet FortiGateRugged-100C

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