Vulnerabilities > CVE-2017-8448 - Improper Privilege Management vulnerability in Elastic X-Pack

047910
CVSS 6.5 - MEDIUM
Attack vector
NETWORK
Attack complexity
LOW
Privileges required
SINGLE
Confidentiality impact
PARTIAL
Integrity impact
PARTIAL
Availability impact
PARTIAL
network
low complexity
elastic
CWE-269
nessus

Summary

An error was found in the permission model used by X-Pack Alerting 5.0.0 to 5.6.0 whereby users mapped to certain built-in roles could create a watch that results in that user gaining elevated privileges.

Common Weakness Enumeration (CWE)

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Restful Privilege Elevation
    Rest uses standard HTTP (Get, Put, Delete) style permissions methods, but these are not necessarily correlated generally with back end programs. Strict interpretation of HTTP get methods means that these HTTP Get services should not be used to delete information on the server, but there is no access control mechanism to back up this logic. This means that unless the services are properly ACL'd and the application's service implementation are following these guidelines then an HTTP request can easily execute a delete or update on the server side. The attacker identifies a HTTP Get URL such as http://victimsite/updateOrder, which calls out to a program to update orders on a database or other resource. The URL is not idempotent so the request can be submitted multiple times by the attacker, additionally, the attacker may be able to exploit the URL published as a Get method that actually performs updates (instead of merely retrieving data). This may result in malicious or inadvertent altering of data on the server.

Nessus

NASL familyCGI abuses
NASL idELASTICSEARCH_ESA_2017_19.NASL
descriptionAn error was found in the permission model used by X-Pack alerting whereby users mapped to certain built-in roles could create a watch that results in that user gaining elevated privileges.
last seen2020-06-01
modified2020-06-02
plugin id112043
published2018-08-22
reporterThis script is Copyright (C) 2018-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
sourcehttps://www.tenable.com/plugins/nessus/112043
titleElasticsearch ESA-2017-19
code
#
# (C) Tenable Network Security, Inc.
#

include("compat.inc");

if (description)
{
  script_id(112043);
  script_version("1.2");
  script_cvs_date("Date: 2019/11/04");

  script_cve_id("CVE-2017-8448");

  script_name(english:"Elasticsearch ESA-2017-19");
  script_summary(english:"Checks the version of Elasticsearch.");

  script_set_attribute(attribute:"synopsis", value:
"The remote web server hosts a Java application that is affected by 
multiple vulnerabilities.");
  script_set_attribute(attribute:"description", value:
"An error was found in the permission model used by X-Pack alerting
whereby users mapped to certain built-in roles could create a watch
that results in that user gaining elevated privileges.");
  script_set_attribute(attribute:"see_also", value:"https://www.elastic.co/community/security");
  script_set_attribute(attribute:"solution", value:
"Deployments of the Elastic Stack that utilize X-Pack alerting should
be upgraded to version 5.6.1 to fix the privilege escalation
issue.Users mapped to the built-in watcher_admin or
machine_learning_admin roles, or any other role to which the
manage_ml or manage_watcher cluster privilege has been assigned,
should be reviewed and granted only to personnel with appropriate
trust levels to read and write all indices.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:S/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:L/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-2017-8448");

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

  script_set_attribute(attribute:"vuln_publication_date", value:"2017/09/18");
  script_set_attribute(attribute:"patch_publication_date", value:"2017/09/18");
  script_set_attribute(attribute:"plugin_publication_date", value:"2018/08/22");

  script_set_attribute(attribute:"plugin_type", value:"remote");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:elastic:x-pack");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2018-2019 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("elasticsearch_detect.nbin");
  script_require_keys("installed_sw/Elasticsearch");
  script_require_ports("Services/www", 9200);

  exit(0);
}

include("audit.inc");
include("http.inc");
include("vcf.inc");

app = "Elasticsearch";

get_install_count(app_name:app, exit_if_zero:TRUE);

port = get_http_port(default:9200);

app_info = vcf::get_app_info(app:app, port:port, webapp:TRUE);

if (empty_or_null(app_info["Plugins/X-Pack/security"]))
  audit(AUDIT_WEB_APP_EXT_NOT_INST, app, app_info['path'], "X-Pack Security plugin");

constraints = [
  { "fixed_version" : "5.6.1" }
];

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