Vulnerabilities > CVE-2018-6356 - Path Traversal vulnerability in multiple products

047910
CVSS 6.5 - MEDIUM
Attack vector
NETWORK
Attack complexity
LOW
Privileges required
LOW
Confidentiality impact
HIGH
Integrity impact
NONE
Availability impact
NONE
network
low complexity
jenkins
oracle
CWE-22
nessus

Summary

Jenkins before 2.107 and Jenkins LTS before 2.89.4 did not properly prevent specifying relative paths that escape a base directory for URLs accessing plugin resource files. This allowed users with Overall/Read permission to download files from the Jenkins master they should not have access to. On Windows, any file accessible to the Jenkins master process could be downloaded. On other operating systems, any file within the Jenkins home directory accessible to the Jenkins master process could be downloaded.

Vulnerable Configurations

Part Description Count
Application
Jenkins
1730
Application
Oracle
1

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Relative Path Traversal
    An attacker exploits a weakness in input validation on the target by supplying a specially constructed path utilizing dot and slash characters for the purpose of obtaining access to arbitrary files or resources. An attacker modifies a known path on the target in order to reach material that is not available through intended channels. These attacks normally involve adding additional path separators (/ or \) and/or dots (.), or encodings thereof, in various combinations in order to reach parent directories or entirely separate trees of the target's directory structure.
  • Directory Traversal
    An attacker with access to file system resources, either directly or via application logic, will use various file path specification or navigation mechanisms such as ".." in path strings and absolute paths to extend their range of access to inappropriate areas of the file system. The attacker attempts to either explore the file system for recon purposes or access directories and files that are intended to be restricted from their access. Exploring the file system can be achieved through constructing paths presented to directory listing programs, such as "ls" and 'dir', or through specially crafted programs that attempt to explore the file system. The attacker engaging in this type of activity is searching for information that can be used later in a more exploitive attack. Access to restricted directories or files can be achieved through modification of path references utilized by system applications.
  • File System Function Injection, Content Based
    An attack of this type exploits the host's trust in executing remote content including binary files. The files are poisoned with a malicious payload (targeting the file systems accessible by the target software) by the attacker and may be passed through standard channels such as via email, and standard web content like PDF and multimedia files. The attacker exploits known vulnerabilities or handling routines in the target processes. Vulnerabilities of this type have been found in a wide variety of commercial applications from Microsoft Office to Adobe Acrobat and Apple Safari web browser. When the attacker knows the standard handling routines and can identify vulnerabilities and entry points they can be exploited by otherwise seemingly normal content. Once the attack is executed, the attackers' program can access relative directories such as C:\Program Files or other standard system directories to launch further attacks. In a worst case scenario, these programs are combined with other propagation logic and work as a virus.
  • Using Slashes and URL Encoding Combined to Bypass Validation Logic
    This attack targets the encoding of the URL combined with the encoding of the slash characters. An attacker can take advantage of the multiple way of encoding an URL and abuse the interpretation of the URL. An URL may contain special character that need special syntax handling in order to be interpreted. Special characters are represented using a percentage character followed by two digits representing the octet code of the original character (%HEX-CODE). For instance US-ASCII space character would be represented with %20. This is often referred as escaped ending or percent-encoding. Since the server decodes the URL from the requests, it may restrict the access to some URL paths by validating and filtering out the URL requests it received. An attacker will try to craft an URL with a sequence of special characters which once interpreted by the server will be equivalent to a forbidden URL. It can be difficult to protect against this attack since the URL can contain other format of encoding such as UTF-8 encoding, Unicode-encoding, etc.
  • Manipulating Input to File System Calls
    An attacker manipulates inputs to the target software which the target software passes to file system calls in the OS. The goal is to gain access to, and perhaps modify, areas of the file system that the target software did not intend to be accessible.

Nessus

  • NASL familyCGI abuses
    NASL idJENKINS_2_107.NASL
    descriptionThe version of Jenkins running on the remote web server is prior to 2.107 or is a version of Jenkins LTS prior to 2.89.4. It is, therefore, affected by multiple vulnerabilities. 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 id106951
    published2018-02-22
    reporterThis script is Copyright (C) 2018-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/106951
    titleJenkins < 2.89.4 / 2.107 Multiple Vulnerabilities
    code
    #
    # (C) Tenable Network Security, Inc.
    #
    
    include("compat.inc");
    
    if (description)
    {
      script_id(106951);
      script_version("1.7");
      script_cvs_date("Date: 2019/11/08");
    
      script_cve_id(
        "CVE-2018-6356",
        "CVE-2018-1000068",
        "CVE-2018-1000102",
        "CVE-2018-1000103"
      );
      script_bugtraq_id(103037, 103101, 103209);
    
      script_name(english:"Jenkins < 2.89.4 / 2.107 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
    2.107 or is a version of Jenkins LTS prior to 2.89.4. It is, therefore,
    affected by multiple vulnerabilities.
    
    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://jenkins.io/security/advisory/2018-02-14/");
      script_set_attribute(attribute:"solution", value:
    "Upgrade Jenkins to version 2.107 or later, Jenkins LTS to version
    2.89.4 or later.");
      script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:N/A:N");
      script_set_cvss_temporal_vector("CVSS2#E:F/RL:OF/RC:ND");
      script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N");
      script_set_cvss3_temporal_vector("CVSS:3.0/E:F/RL:O/RC:X");
      script_set_attribute(attribute:"cvss_score_source", value:"CVE-2018-1000068");
    
      script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
      script_set_attribute(attribute:"exploit_available", value:"true");
    
      script_set_attribute(attribute:"vuln_publication_date", value:"2018/02/14");
      script_set_attribute(attribute:"patch_publication_date", value:"2018/02/14");
      script_set_attribute(attribute:"plugin_publication_date", value:"2018/02/22");
    
      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) 2018-2019 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+"/is_LTS") )
    {
      appname = "Jenkins Open Source LTS";
      fix = '2.89.4';
    }
    else
    {
      appname = "Jenkins Open Source";
      fix = '2.107';
    }
    
    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_WARNING, extra:report, xsrf:TRUE);
    }
    else audit(AUDIT_WEB_APP_NOT_AFFECTED, appname, url, version);
    
  • NASL familyFreeBSD Local Security Checks
    NASL idFREEBSD_PKG_5D374FBBBAE345DBAFC0795684AC7353.NASL
    descriptionJenkins developers report : Jenkins did not properly prevent specifying relative paths that escape a base directory for URLs accessing plugin resource files. This allowed users with Overall/Read permission to download files from the Jenkins master they should not have access to.
    last seen2020-06-01
    modified2020-06-02
    plugin id106832
    published2018-02-15
    reporterThis script is Copyright (C) 2018-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/106832
    titleFreeBSD : jenkins -- Path traversal vulnerability allows access to files outside plugin resources (5d374fbb-bae3-45db-afc0-795684ac7353)
    code
    #
    # (C) Tenable Network Security, Inc.
    #
    # The descriptive text and package checks in this plugin were  
    # extracted from the FreeBSD VuXML database :
    #
    # Copyright 2003-2019 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(106832);
      script_version("3.9");
      script_cvs_date("Date: 2019/07/10 16:04:13");
    
      script_cve_id("CVE-2018-6356");
    
      script_name(english:"FreeBSD : jenkins -- Path traversal vulnerability allows access to files outside plugin resources (5d374fbb-bae3-45db-afc0-795684ac7353)");
      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 developers report :
    
    Jenkins did not properly prevent specifying relative paths that escape
    a base directory for URLs accessing plugin resource files. This
    allowed users with Overall/Read permission to download files from the
    Jenkins master they should not have access to."
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://jenkins.io/security/advisory/2018-02-14/"
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://jenkins.io/blog/2018/02/14/security-updates/"
      );
      # https://vuxml.freebsd.org/freebsd/5d374fbb-bae3-45db-afc0-795684ac7353.html
      script_set_attribute(
        attribute:"see_also",
        value:"http://www.nessus.org/u?6e2fb1b7"
      );
      script_set_attribute(attribute:"solution", value:"Update the affected packages.");
      script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:S/C:P/I:N/A:N");
      script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N");
    
      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:"2018/02/14");
      script_set_attribute(attribute:"patch_publication_date", value:"2018/02/14");
      script_set_attribute(attribute:"plugin_publication_date", value:"2018/02/15");
      script_set_attribute(attribute:"generated_plugin", value:"current");
      script_end_attributes();
    
      script_category(ACT_GATHER_INFO);
      script_copyright(english:"This script is Copyright (C) 2018-2019 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<=2.106")) flag++;
    if (pkg_test(save_report:TRUE, pkg:"jenkins-lts<=2.89.3")) flag++;
    
    if (flag)
    {
      if (report_verbosity > 0) security_warning(port:0, extra:pkg_report_get());
      else security_warning(0);
      exit(0);
    }
    else audit(AUDIT_HOST_NOT, "affected");