Vulnerabilities > CVE-2017-1000354 - Improper Authentication vulnerability in Jenkins

047910
CVSS 8.8 - HIGH
Attack vector
NETWORK
Attack complexity
LOW
Privileges required
LOW
Confidentiality impact
HIGH
Integrity impact
HIGH
Availability impact
HIGH
network
low complexity
jenkins
CWE-287
nessus
NVD
Published: 2018-01-29
Updated: 2018-02-15

Summary

Jenkins versions 2.56 and earlier as well as 2.46.1 LTS and earlier are vulnerable to a login command which allowed impersonating any Jenkins user. The `login` command available in the remoting-based CLI stored the encrypted user name of the successfully authenticated user in a cache file used to authenticate further commands. Users with sufficient permission to create secrets in Jenkins, and download their encrypted values (e.g. with Job/Configure permission), were able to impersonate any other Jenkins user on the same instance.

Vulnerable Configurations

Part Description Count
Application
Jenkins
1554

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 idJENKINS_2_57.NASL
    descriptionThe version of Jenkins running on the remote web server is prior to 2.57 or is a version of Jenkins LTS prior to 2.46.2, or else it is a version of Jenkins Enterprise that is 1.625.x.y prior to 1.625.24.1, 1.651.x.y prior to 1.651.24.1, 2.7.x.0.y prior to 2.7.24.0.1, or 2.x.y.z prior to 2.46.2.1. It is, therefore, affected by multiple vulnerabilities : - A remote code execution vulnerability exists within core/src/main/java/jenkins/model/Jenkins.java that allows an untrusted serialized Java SignedObject to be transfered to the remoting-based Jenkins CLI and deserialized using a new ObjectInputStream. By using a specially crafted request, an unauthenticated, remote attacker can exploit this issue to bypass existing blacklist protection mechanisms and execute arbitrary code. (CVE-2017-1000353) - A flaw exists in the remoting-based CLI, specifically in the ClientAuthenticationCache.java class, when storing the encrypted username of a successfully authenticated user in a cache file that is used to authenticate further commands. An authenticated, remote attacker who has sufficient permissions to create secrets in Jenkins and download their encrypted values can exploit this issue to impersonate any other Jenkins user on the same instance. (CVE-2017-1000354) - A denial of service vulnerability exists in the XStream library. An authenticated, remote attacker who has sufficient permissions, such as creating or configuring items, views or jobs, can exploit this to crash the Java process by using specially crafted XML content. (CVE-2017-1000355) - Cross-site request forgery (XSRF) vulnerabilities exist within multiple Java classes due to a failure to require multiple steps, explicit confirmation, or a unique token when performing certain sensitive actions. An unauthenticated, remote attacker can exploit these to perform several administrative actions by convincing a user into opening a specially crafted web page. (CVE-2017-1000356) Note that Nessus has not tested for these issues but has instead relied only on the application
    last seen2020-06-01
    modified2020-06-02
    plugin id99984
    published2017-05-04
    reporterThis script is Copyright (C) 2017-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/99984
    titleJenkins < 2.46.2 / 2.57 and Jenkins Enterprise < 1.625.24.1 / 1.651.24.1 / 2.7.24.0.1 / 2.46.2.1 Multiple Vulnerabilities
    code
    #
# (C) Tenable Network Security, Inc.
#

include("compat.inc");

if (description)
{
  script_id(99984);
  script_version("1.8");
  script_cvs_date("Date: 2019/11/13");

  script_cve_id(
    "CVE-2017-1000353",
    "CVE-2017-1000354",
    "CVE-2017-1000355",
    "CVE-2017-1000356"
  );
  script_bugtraq_id(
    98056,
    98062,
    98065,
    98066
  );

  script_name(english:"Jenkins < 2.46.2 / 2.57 and Jenkins Enterprise < 1.625.24.1 / 1.651.24.1 / 2.7.24.0.1 / 2.46.2.1 Multiple Vulnerabilities");
  script_summary(english:"Checks the Jenkins version.");

  script_set_attribute(attribute:"synopsis", value:
"A job scheduling and management system hosted on the remote web server
is affected by multiple vulnerabilities.");
  script_set_attribute(attribute:"description", value:
"The version of Jenkins running on the remote web server is prior to
2.57 or is a version of Jenkins LTS prior to 2.46.2, or else it is
a version of Jenkins Enterprise that is 1.625.x.y prior to 1.625.24.1,
1.651.x.y prior to 1.651.24.1, 2.7.x.0.y prior to 2.7.24.0.1, or
2.x.y.z prior to 2.46.2.1. It is, therefore, affected by multiple
vulnerabilities :

  - A remote code execution vulnerability exists within
    core/src/main/java/jenkins/model/Jenkins.java that
    allows an untrusted serialized Java SignedObject to be
    transfered to the remoting-based Jenkins CLI and
    deserialized using a new ObjectInputStream. By using a
    specially crafted request, an unauthenticated, remote
    attacker can exploit this issue to bypass existing
    blacklist protection mechanisms and execute arbitrary
    code. (CVE-2017-1000353)

  - A flaw exists in the remoting-based CLI, specifically in
    the ClientAuthenticationCache.java class, when storing
    the encrypted username of a successfully authenticated
    user in a cache file that is used to authenticate
    further commands. An authenticated, remote attacker who
    has sufficient permissions to create secrets in Jenkins
    and download their encrypted values can exploit this
    issue to impersonate any other Jenkins user on the same
    instance. (CVE-2017-1000354)

  - A denial of service vulnerability exists in the XStream
    library. An authenticated, remote attacker who has
    sufficient permissions, such as creating or configuring
    items, views or jobs, can exploit this to crash the Java
    process by using specially crafted XML content.
    (CVE-2017-1000355)

  - Cross-site request forgery (XSRF) vulnerabilities exist
    within multiple Java classes due to a failure to require
    multiple steps, explicit confirmation, or a unique token
    when performing certain sensitive actions. An
    unauthenticated, remote attacker can exploit these to
    perform several administrative actions by convincing a
    user into opening a specially crafted web page.
    (CVE-2017-1000356)

Note that Nessus has not tested for these issues but has instead
relied only on the application's self-reported version number.");
  script_set_attribute(attribute:"see_also", value:"https://www.cloudbees.com/cloudbees-security-advisory-2017-04-26");
  script_set_attribute(attribute:"see_also", value:"https://jenkins.io/security/advisory/2017-04-26/");
  # https://foxglovesecurity.com/2015/11/06/what-do-weblogic-websphere-jboss-jenkins-opennms-and-your-application-have-in-common-this-vulnerability/
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?9c6d83db");
  script_set_attribute(attribute:"solution", value:
"Upgrade Jenkins to version 2.57 or later, Jenkins LTS to version
2.46.2 or later, or Jenkins Enterprise to version 1.625.24.1 /
1.651.24.1 / 2.7.24.0.1 / 2.46.2.1 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:H/RL:OF/RC:ND");
  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:H/RL:O/RC:X");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2017-1000353");

  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");
  script_set_attribute(attribute:"in_the_news", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2017/04/13");
  script_set_attribute(attribute:"patch_publication_date", value:"2017/04/26");
  script_set_attribute(attribute:"plugin_publication_date", value:"2017/05/04");

  script_set_attribute(attribute:"plugin_type", value:"remote");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:cloudbees:jenkins");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2017-2019 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("jenkins_detect.nasl");
  script_require_keys("www/Jenkins");
  script_require_ports("Services/www", 8080);

  exit(0);
}

include("audit.inc");
include("global_settings.inc");
include("misc_func.inc");
include("http.inc");

port = get_http_port(default:8080);
get_kb_item_or_exit("www/Jenkins/"+port+"/Installed");
url = build_url(qs:'/', port:port);

version = '';
fix = '';
if (get_kb_item("www/Jenkins/"+port+"/enterprise/Installed"))
{
  appname = "Jenkins Enterprise by CloudBees";
  version = get_kb_item("www/Jenkins/"+port+"/enterprise/CloudBeesVersion");

  if (version =~ "^1\.651\.")
  {
    fix = '1.651.24.1';
  }
  else if (version =~ "^1\.625\." )
  {
    fix = '1.625.24.1';
  }
  else if (version =~ "^2\.7\." )
  {
    fix = '2.7.24.0.1';
  }
  else
  {
    fix = '2.46.2.1';
  }
}
else
{
  if (get_kb_item("www/Jenkins/"+port+"/is_LTS") )
  {
    appname = "Jenkins Open Source LTS";
    fix = '2.46.2';
  }
  else
  {
    appname = "Jenkins Open Source";
    fix = '2.57';
  }

  version = get_kb_item("www/Jenkins/" + port + "/JenkinsVersion");
  if (version == 'unknown')
  {
    audit(AUDIT_UNKNOWN_WEB_APP_VER, appname, url);
  }
}

if (ver_compare(ver:version, fix:fix, strict:FALSE) < 0)
{
  report =
    '\n  URL           : ' + url +
    '\n  Product       : ' + appname +
    '\n  Version       : ' + version +
    '\n  Fixed version : ' + fix +
    '\n';

  security_report_v4(port:port, severity:SECURITY_HOLE, extra:report, xsrf:TRUE);
}
else audit(AUDIT_WEB_APP_NOT_AFFECTED, appname, url, version);
  • NASL familyFreeBSD Local Security Checks
    NASL idFREEBSD_PKG_631C47109BE54A809310EB2847FE24DD.NASL
    descriptionJenkins Security Advisory : DescriptionSECURITY-412 through SECURITY-420 / CVE-2017-1000356 CSRF: Multiple vulnerabilities SECURITY-429 / CVE-2017-1000353 CLI: Unauthenticated remote code execution SECURITY-466 / CVE-2017-1000354 CLI: Login command allowed impersonating any Jenkins user SECURITY-503 / CVE-2017-1000355 XStream: Java crash when trying to instantiate void/Void
    last seen2020-06-01
    modified2020-06-02
    plugin id99698
    published2017-04-27
    reporterThis script is Copyright (C) 2017-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/99698
    titleFreeBSD : jenkins -- multiple vulnerabilities (631c4710-9be5-4a80-9310-eb2847fe24dd)
    code
    #
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were  
# extracted from the FreeBSD VuXML database :
#
# Copyright 2003-2018 Jacques Vidrine and contributors
#
# Redistribution and use in source (VuXML) and 'compiled' forms (SGML,
# HTML, PDF, PostScript, RTF and so forth) with or without modification,
# are permitted provided that the following conditions are met:
# 1. Redistributions of source code (VuXML) must retain the above
#    copyright notice, this list of conditions and the following
#    disclaimer as the first lines of this file unmodified.
# 2. Redistributions in compiled form (transformed to other DTDs,
#    published online in any format, converted to PDF, PostScript,
#    RTF and other formats) must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer
#    in the documentation and/or other materials provided with the
#    distribution.
# 
# THIS DOCUMENTATION IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
# THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
# PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS
# BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
# OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
# OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
# BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
# WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
# OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS DOCUMENTATION,
# EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#

include("compat.inc");

if (description)
{
  script_id(99698);
  script_version("3.5");
  script_cvs_date("Date: 2019/04/10 16:10:17");

  script_cve_id("CVE-2017-1000353", "CVE-2017-1000354", "CVE-2017-1000355", "CVE-2017-1000356");

  script_name(english:"FreeBSD : jenkins -- multiple vulnerabilities (631c4710-9be5-4a80-9310-eb2847fe24dd)");
  script_summary(english:"Checks for updated packages in pkg_info output");

  script_set_attribute(
    attribute:"synopsis", 
    value:
"The remote FreeBSD host is missing one or more security-related
updates."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"Jenkins Security Advisory : DescriptionSECURITY-412 through
SECURITY-420 / CVE-2017-1000356 CSRF: Multiple vulnerabilities
SECURITY-429 / CVE-2017-1000353 CLI: Unauthenticated remote code
execution SECURITY-466 / CVE-2017-1000354 CLI: Login command allowed
impersonating any Jenkins user SECURITY-503 / CVE-2017-1000355
XStream: Java crash when trying to instantiate void/Void"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://jenkins.io/security/advisory/2017-04-26/"
  );
  # https://vuxml.freebsd.org/freebsd/631c4710-9be5-4a80-9310-eb2847fe24dd.html
  script_set_attribute(
    attribute:"see_also",
    value:"http://www.nessus.org/u?3062337c"
  );
  script_set_attribute(attribute:"solution", value:"Update the affected packages.");
  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:POC/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:P/RL:O/RC:C");
  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:freebsd:freebsd:jenkins");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:freebsd:freebsd:jenkins-lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:freebsd:freebsd");

  script_set_attribute(attribute:"vuln_publication_date", value:"2017/04/26");
  script_set_attribute(attribute:"patch_publication_date", value:"2017/04/27");
  script_set_attribute(attribute:"plugin_publication_date", value:"2017/04/27");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2017-2019 and is owned by Tenable, Inc. or an Affiliate thereof.");
  script_family(english:"FreeBSD Local Security Checks");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/FreeBSD/release", "Host/FreeBSD/pkg_info");

  exit(0);
}


include("audit.inc");
include("freebsd_package.inc");


if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
if (!get_kb_item("Host/FreeBSD/release")) audit(AUDIT_OS_NOT, "FreeBSD");
if (!get_kb_item("Host/FreeBSD/pkg_info")) audit(AUDIT_PACKAGE_LIST_MISSING);


flag = 0;

if (pkg_test(save_report:TRUE, pkg:"jenkins<2.57")) flag++;
if (pkg_test(save_report:TRUE, pkg:"jenkins-lts<2.46.2")) flag++;

if (flag)
{
  if (report_verbosity > 0) security_hole(port:0, extra:pkg_report_get());
  else security_hole(0);
  exit(0);
}
else audit(AUDIT_HOST_NOT, "affected");

Seebug

bulletinFamilyexploit
descriptionThe login command available in the remoting-based CLI stored the encrypted user name of the successfully authenticated user in a cache file used to authenticate further commands. Users with sufficient permission to create secrets in Jenkins, and download their encrypted values (e.g. with Job/Configure permission), were able to impersonate any other Jenkins user on the same instance. This has been fixed by storing the cached authentication as a hash-based MAC with a key specific to the Jenkins instance and the CLI authentication cache. Previously cached authentications are invalidated when upgrading Jenkins to a version containing a fix for this.
idSSV:93064
last seen2017-11-19
modified2017-04-28
published2017-04-28
reporterRoot
titleJenkins CLI: Login command allowed impersonating any Jenkins user (CVE-2017-1000354)

References