Vulnerabilities > CVE-2017-2297 - Improper Authentication vulnerability in Puppet Enterprise

047910
CVSS 6.0 - MEDIUM
Attack vector
NETWORK
Attack complexity
MEDIUM
Privileges required
SINGLE
Confidentiality impact
PARTIAL
Integrity impact
PARTIAL
Availability impact
PARTIAL
network
puppet
CWE-287
nessus

Summary

Puppet Enterprise versions prior to 2016.4.5 and 2017.2.1 did not correctly authenticate users before returning labeled RBAC access tokens. This issue has been fixed in Puppet Enterprise 2016.4.5 and 2017.2.1. This only affects users with labeled tokens, which is not the default for tokens.

Vulnerable Configurations

Part Description Count
Application
Puppet
75

Common Weakness Enumeration (CWE)

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Authentication Abuse
    An attacker obtains unauthorized access to an application, service or device either through knowledge of the inherent weaknesses of an authentication mechanism, or by exploiting a flaw in the authentication scheme's implementation. In such an attack an authentication mechanism is functioning but a carefully controlled sequence of events causes the mechanism to grant access to the attacker. This attack may exploit assumptions made by the target's authentication procedures, such as assumptions regarding trust relationships or assumptions regarding the generation of secret values. This attack differs from Authentication Bypass attacks in that Authentication Abuse allows the attacker to be certified as a valid user through illegitimate means, while Authentication Bypass allows the user to access protected material without ever being certified as an authenticated user. This attack does not rely on prior sessions established by successfully authenticating users, as relied upon for the "Exploitation of Session Variables, Resource IDs and other Trusted Credentials" attack patterns.
  • Exploiting Trust in Client (aka Make the Client Invisible)
    An attack of this type exploits a programs' vulnerabilities in client/server communication channel authentication and data integrity. It leverages the implicit trust a server places in the client, or more importantly, that which the server believes is the client. An attacker executes this type of attack by placing themselves in the communication channel between client and server such that communication directly to the server is possible where the server believes it is communicating only with a valid client. There are numerous variations of this type of attack.
  • Utilizing REST's Trust in the System Resource to Register Man in the Middle
    This attack utilizes a REST(REpresentational State Transfer)-style applications' trust in the system resources and environment to place man in the middle once SSL is terminated. Rest applications premise is that they leverage existing infrastructure to deliver web services functionality. An example of this is a Rest application that uses HTTP Get methods and receives a HTTP response with an XML document. These Rest style web services are deployed on existing infrastructure such as Apache and IIS web servers with no SOAP stack required. Unfortunately from a security standpoint, there frequently is no interoperable identity security mechanism deployed, so Rest developers often fall back to SSL to deliver security. In large data centers, SSL is typically terminated at the edge of the network - at the firewall, load balancer, or router. Once the SSL is terminated the HTTP request is in the clear (unless developers have hashed or encrypted the values, but this is rare). The attacker can utilize a sniffer such as Wireshark to snapshot the credentials, such as username and password that are passed in the clear once SSL is terminated. Once the attacker gathers these credentials, they can submit requests to the web service provider just as authorized user do. There is not typically an authentication on the client side, beyond what is passed in the request itself so once this is compromised, then this is generally sufficient to compromise the service's authentication scheme.
  • Man in the Middle Attack
    This type of attack targets the communication between two components (typically client and server). The attacker places himself in the communication channel between the two components. Whenever one component attempts to communicate with the other (data flow, authentication challenges, etc.), the data first goes to the attacker, who has the opportunity to observe or alter it, and it is then passed on to the other component as if it was never intercepted. This interposition is transparent leaving the two compromised components unaware of the potential corruption or leakage of their communications. The potential for Man-in-the-Middle attacks yields an implicit lack of trust in communication or identify between two components.

Nessus

NASL familyCGI abuses
NASL idPUPPET_ENTERPRISE_2016_4_5.NASL
descriptionAccording to its self-reported version number, the Puppet install on the remote host is affected by multiple vulnerabilities : - A remote command execution vulnerability exists in the MCollective plugin due to unsafe YAML deserialization. An unauthenticated, remote attacker can exploit this to bypass authentication and execute arbitrary commands. (CVE-2017-2292, CVE-2017-2295) - An arbitrary package install vulnerability exists in the MCollective plugin due to unsafe default configuration. An unauthenticated, remote attacker can exploit this to install or remove packages on all managed agents. (CVE-2017-2293) - An information disclosure vulnerability exists in the MCollective plugin due to unsafe storage of server private keys. An unauthenticated, remote attacker can exploit this to view sensitive private keys. (CVE-2017-2294) - An authentication bypass vulnerability exists in labled RBAC access tokens. An unauthenticated, attacker can exploit this, to bypass authentication and execute arbitrary actions of users configured to use labeled RBAC access tokens. This issue has been fixed in Puppet Enterprise 2016.4.5 and 2017.2.1. This only affects users with labeled tokens, which is not the default for tokens. (CVE-2017-2297)
last seen2020-06-01
modified2020-06-02
plugin id129755
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/129755
titlePuppet Enterprise < 2016.4.5 / 2016.5.x / 2017.1.x Multiple Vulnerabilities
code
#
# (C) Tenable Network Security, Inc.
#

include("compat.inc");

if (description)
{
  script_id(129755);
  script_version("1.2");
  script_cvs_date("Date: 2019/10/17 14:31:04");

  script_cve_id(
    "CVE-2017-2292",
    "CVE-2017-2293",
    "CVE-2017-2294",
    "CVE-2017-2295",
    "CVE-2017-2297"
  );
  script_bugtraq_id(98582);

  script_name(english:"Puppet Enterprise < 2016.4.5 / 2016.5.x / 2017.1.x 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 install on
the remote host is affected by multiple vulnerabilities :

  - A remote command execution vulnerability exists in the MCollective plugin
    due to unsafe YAML deserialization. An unauthenticated, remote attacker 
    can exploit this to bypass authentication and execute arbitrary commands. 
    (CVE-2017-2292, CVE-2017-2295)

  - An arbitrary package install vulnerability exists in the MCollective plugin
    due to unsafe default configuration. An unauthenticated, remote attacker 
    can exploit this to install or remove packages on all managed agents.
    (CVE-2017-2293)

  - An information disclosure vulnerability exists in the MCollective plugin
    due to unsafe storage of server private keys. An unauthenticated, remote attacker 
    can exploit this to view sensitive private keys.
    (CVE-2017-2294)
  
  - An authentication bypass vulnerability exists in labled RBAC access tokens. 
    An unauthenticated, attacker can exploit this, to bypass authentication 
    and execute arbitrary actions of users configured to use labeled RBAC
    access tokens. This issue has been fixed in Puppet Enterprise 2016.4.5 
    and 2017.2.1. This only affects users with labeled tokens, which is 
    not the default for tokens. (CVE-2017-2297)");
  script_set_attribute(attribute:"see_also", value:"https://puppet.com/security/cve/CVE-2017-2292");
  script_set_attribute(attribute:"see_also", value:"https://puppet.com/security/cve/CVE-2017-2293");
  script_set_attribute(attribute:"see_also", value:"https://puppet.com/security/cve/CVE-2017-2294");
  script_set_attribute(attribute:"see_also", value:"https://puppet.com/security/cve/CVE-2017-2295");
  script_set_attribute(attribute:"see_also", value:"https://puppet.com/security/cve/CVE-2017-2297");
  script_set_attribute(attribute:"solution", value:
"Upgrade to Puppet Enterprise version 2016.4.5 / 2017.2.1 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:H/UI:N/S:C/C:H/I:H/A:L");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2017-2292");

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

  script_set_attribute(attribute:"vuln_publication_date", value:"2017/05/11");
  script_set_attribute(attribute:"patch_publication_date", value:"2017/05/11");
  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/2018.1/component_versions_in_recent_pe_releases.html
constraints = [
  {"min_version" : "4.0.0", "fixed_version" : "4.10.1", "fixed_display" : "Puppet Enterprise (2016.4.5 / 2017.2.1)"}
];

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