Vulnerabilities > CVE-2015-4100 - Improper Certificate Validation vulnerability in Puppet Enterprise
Attack vector
NETWORK Attack complexity
HIGH Privileges required
LOW Confidentiality impact
HIGH Integrity impact
NONE Availability impact
HIGH Summary
Puppet Enterprise 3.7.x and 3.8.0 might allow remote authenticated users to manage certificates for arbitrary nodes by leveraging a client certificate trusted by the master, aka a "Certificate Authority Reverse Proxy Vulnerability."
Vulnerable Configurations
| Part | Description | Count |
|---|---|---|
| Application | 4 |
Common Weakness Enumeration (CWE)
Common Attack Pattern Enumeration and Classification (CAPEC)
- Creating a Rogue Certificate Authority Certificate An attacker exploits a weakness in the MD5 hash algorithm (weak collision resistance) to generate a certificate signing request (CSR) that contains collision blocks in the "to be signed" part. The attacker specially crafts two different, but valid X.509 certificates that when hashed with the MD5 algorithm would yield the same value. The attacker then sends the CSR for one of the certificates to the Certification Authority which uses the MD5 hashing algorithm. That request is completely valid and the Certificate Authority issues an X.509 certificate to the attacker which is signed with its private key. An attacker then takes that signed blob and inserts it into another X.509 certificate that the attacker generated. Due to the MD5 collision, both certificates, though different, hash to the same value and so the signed blob works just as well in the second certificate. The net effect is that the attackers' second X.509 certificate, which the Certification Authority has never seen, is now signed and validated by that Certification Authority. To make the attack more interesting, the second certificate could be not just a regular certificate, but rather itself a signing certificate. Thus the attacker is able to start their own Certification Authority that is anchored in its root of trust in the legitimate Certification Authority that has signed the attackers' first X.509 certificate. If the original Certificate Authority was accepted by default by browsers, so will now the Certificate Authority set up by the attacker and of course any certificates that it signs. So the attacker is now able to generate any SSL certificates to impersonate any web server, and the user's browser will not issue any warning to the victim. This can be used to compromise HTTPS communications and other types of systems where PKI and X.509 certificates may be used (e.g., VPN, IPSec) .
Nessus
| NASL family | CGI abuses |
| NASL id | PUPPET_ENTERPRISE_CVE_2015-4100.NASL |
| description | According to its self-reported version number, the Puppet Enterprise application running on the remote host is version 3.7.x or 3.8.x prior to 3.8.1. It it, therefore, affected by the following vulnerabilities : - A flaw exists in RubyGems due to a failure to validate hostnames when fetching gems or making API requests. A remote attacker, using a crafted DNS SRV record, can exploit this to redirect requests to arbitrary domains. (CVE-2015-3900) - A flaw exists in RubyGems due to a failure to sanitize DNS responses, which allows a man-in-the-middle attacker to install arbitrary applications. (CVE-2015-4020) - A flaw exists in Puppet Enterprise related to how certificates are managed, under certain vulnerable configurations, which allows a trusted certificate to be used to perform full certificate management. An attacker can exploit this flaw to revoke the certificates of other nodes or to approve their certificate requests. (CVE-2015-4100) Note that the default |
| last seen | 2020-06-01 |
| modified | 2020-06-02 |
| plugin id | 84961 |
| published | 2015-07-23 |
| reporter | This script is Copyright (C) 2015-2019 and is owned by Tenable, Inc. or an Affiliate thereof. |
| source | https://www.tenable.com/plugins/nessus/84961 |
| title | Puppet Enterprise 3.7.x < 3.8.1 / 3.8.x < 3.8.1 Multiple Vulnerabilities |
| code | |