Vulnerabilities > CVE-2016-2787 - Improper Access Control vulnerability in multiple products

047910
CVSS 5.3 - MEDIUM
Attack vector
NETWORK
Attack complexity
LOW
Privileges required
NONE
Confidentiality impact
NONE
Integrity impact
NONE
Availability impact
LOW
network
low complexity
puppetlabs
puppet
CWE-284
nessus

Summary

The Puppet Communications Protocol in Puppet Enterprise 2015.3.x before 2015.3.3 does not properly validate certificates for the broker node, which allows remote non-whitelisted hosts to prevent runs from triggering via unspecified vectors.

Vulnerable Configurations

Part Description Count
Application
Puppetlabs
1
Application
Puppet
1

Common Weakness Enumeration (CWE)

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Embedding Scripts within Scripts
    An attack of this type exploits a programs' vulnerabilities that are brought on by allowing remote hosts to execute scripts. The attacker leverages this capability to execute scripts to execute his/her own script by embedding it within other scripts that the target software is likely to execute. The attacker must have the ability to inject script into script that is likely to be executed. If this is done, then the attacker can potentially launch a variety of probes and attacks against the web server's local environment, in many cases the so-called DMZ, back end resources the web server can communicate with, and other hosts. With the proliferation of intermediaries, such as Web App Firewalls, network devices, and even printers having JVMs and Web servers, there are many locales where an attacker can inject malicious scripts. Since this attack pattern defines scripts within scripts, there are likely privileges to execute said attack on the host. Of course, these attacks are not solely limited to the server side, client side scripts like Ajax and client side JavaScript can contain malicious scripts as well. In general all that is required is for there to be sufficient privileges to execute a script, but not protected against writing.
  • Signature Spoofing by Key Theft
    An attacker obtains an authoritative or reputable signer's private signature key by theft and then uses this key to forge signatures from the original signer to mislead a victim into performing actions that benefit the attacker.

Nessus

NASL familyCGI abuses
NASL idPUPPET_ENTERPRISE_2015_3_3.NASL
descriptionAccording to its self-reported version number, the Puppet Enterprise application running on the remote host is version 2015.x prior to 2015.3.3. It is, therefore, affected by the following vulnerabilities : - A invalid validation of the server certificate by the pxp-agent. An unauthenticated, remote attacker can impersonate a broker and issue commands to the agent. This requires a secondary attack which forces the agent to connect to the malicious broker. (CVE-2016-2786) - A denial of service vulnerability exists due to the incorrect validation of the broker node certificates. An unauthenticated, remote attacker can prevent the puppet communications protocol from triggering runs. (CVE-2016-2787)
last seen2020-06-01
modified2020-06-02
plugin id129752
published2019-10-09
reporterThis script is Copyright (C) 2019 and is owned by Tenable, Inc. or an Affiliate thereof.
sourcehttps://www.tenable.com/plugins/nessus/129752
titlePuppet Enterprise 2015.x < 2015.3.3 Multiple Vulnerabilities
code
#
# (C) Tenable Network Security, Inc.
#

include("compat.inc");

if (description)
{
  script_id(129752);
  script_version("1.2");
  script_cvs_date("Date: 2019/10/17 14:31:04");

  script_cve_id("CVE-2016-2786", "CVE-2016-2787");
  script_bugtraq_id(91163, 96359);

  script_name(english:"Puppet Enterprise 2015.x < 2015.3.3 Multiple Vulnerabilities");
  script_summary(english:"Checks the Puppet Enterprise version.");

  script_set_attribute(attribute:"synopsis", value:
"A web application running on the remote host is affected by multiple
vulnerabilities.");
  script_set_attribute(attribute:"description", value:
"According to its self-reported version number, the Puppet Enterprise
application running on the remote host is version 2015.x 
prior to 2015.3.3. It is, therefore, affected by the following 
vulnerabilities :

  - A invalid validation of the server certificate by the pxp-agent. 
    An unauthenticated, remote attacker can impersonate a broker and 
    issue commands to the agent. This requires a secondary attack 
    which forces the agent to connect to the malicious broker.
    (CVE-2016-2786)

  - A denial of service vulnerability exists due to the incorrect
    validation of the broker node certificates.  An unauthenticated, 
    remote attacker can prevent the puppet communications protocol 
    from triggering runs.  (CVE-2016-2787)");
  script_set_attribute(attribute:"see_also", value:"https://puppet.com/security/cve/cve-2016-2786");
  script_set_attribute(attribute:"see_also", value:"https://puppet.com/security/cve/cve-2016-2787");
  script_set_attribute(attribute:"solution", value:
"Upgrade to Puppet Enterprise version 2015.3.3 or later.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2016-2786");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");

  script_set_attribute(attribute:"vuln_publication_date", value:"2016/03/14");
  script_set_attribute(attribute:"patch_publication_date", value:"2016/03/14");
  script_set_attribute(attribute:"plugin_publication_date", value:"2019/10/09");

  script_set_attribute(attribute:"plugin_type", value:"remote");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:puppetlabs:puppet");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"CGI abuses");

  script_copyright(english:"This script is Copyright (C) 2019 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("puppet_enterprise_console_detect.nasl", "puppet_rest_detect.nasl");
  script_require_keys("puppet/rest_port", "installed_sw/puppet_enterprise_console");

  exit(0);
}

include('vcf.inc');
include('http.inc');

app = 'Puppet REST API'; # we get both enterprise and open-source versions from the api...

# Make sure we detected a version 
port = get_kb_item_or_exit('puppet/rest_port');
ver = get_kb_item_or_exit('puppet/' + port + '/version');

# Make sure the Console service is running
get_kb_item_or_exit('installed_sw/puppet_enterprise_console');

app_info = vcf::get_app_info(app:app, port:port, webapp:TRUE, kb_ver: 'puppet/' + port + '/version');

# version info obtained from https://puppet.com/docs/pe/2016.2/overview_version_table.html
constraints = [
  {"min_version" : "4.3.0", "fixed_version" : "4.3.2", "fixed_display" : "Puppet Enterprise (2015.3.3)"}
];

vcf::check_version_and_report(app_info:app_info, constraints:constraints, severity:SECURITY_HOLE);