Vulnerabilities > CVE-2020-2106 - Cross-site Scripting vulnerability in Jenkins Code Coverage API

047910
CVSS 5.4 - MEDIUM
Attack vector
NETWORK
Attack complexity
LOW
Privileges required
LOW
Confidentiality impact
LOW
Integrity impact
LOW
Availability impact
NONE
network
low complexity
jenkins
CWE-79
nessus

Summary

Jenkins Code Coverage API Plugin 1.1.2 and earlier does not escape the filename of the coverage report used in its view, resulting in a stored XSS vulnerability exploitable by users able to change job configurations.

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Cross Site Scripting through Log Files
    An attacker may leverage a system weakness where logs are susceptible to log injection to insert scripts into the system's logs. If these logs are later viewed by an administrator through a thin administrative interface and the log data is not properly HTML encoded before being written to the page, the attackers' scripts stored in the log will be executed in the administrative interface with potentially serious consequences. This attack pattern is really a combination of two other attack patterns: log injection and stored cross site scripting.
  • Embedding Scripts in Non-Script Elements
    This attack is a form of Cross-Site Scripting (XSS) where malicious scripts are embedded in elements that are not expected to host scripts such as image tags (<img>), comments in XML documents (< !-CDATA->), etc. These tags may not be subject to the same input validation, output validation, and other content filtering and checking routines, so this can create an opportunity for an attacker to tunnel through the application's elements and launch a XSS attack through other elements. As with all remote attacks, it is important to differentiate the ability to launch an attack (such as probing an internal network for unpatched servers) and the ability of the remote attacker to collect and interpret the output of said attack.
  • 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.
  • Cross-Site Scripting in Error Pages
    An attacker distributes a link (or possibly some other query structure) with a request to a third party web server that is malformed and also contains a block of exploit code in order to have the exploit become live code in the resulting error page. When the third party web server receives the crafted request and notes the error it then creates an error message that echoes the malformed message, including the exploit. Doing this converts the exploit portion of the message into to valid language elements that are executed by the viewing browser. When a victim executes the query provided by the attacker the infected error message error message is returned including the exploit code which then runs in the victim's browser. XSS can result in execution of code as well as data leakage (e.g. session cookies can be sent to the attacker). This type of attack is especially dangerous since the exploit appears to come from the third party web server, who the victim may trust and hence be more vulnerable to deception.
  • Cross-Site Scripting Using Alternate Syntax
    The attacker uses alternate forms of keywords or commands that result in the same action as the primary form but which may not be caught by filters. For example, many keywords are processed in a case insensitive manner. If the site's web filtering algorithm does not convert all tags into a consistent case before the comparison with forbidden keywords it is possible to bypass filters (e.g., incomplete black lists) by using an alternate case structure. For example, the "script" tag using the alternate forms of "Script" or "ScRiPt" may bypass filters where "script" is the only form tested. Other variants using different syntax representations are also possible as well as using pollution meta-characters or entities that are eventually ignored by the rendering engine. The attack can result in the execution of otherwise prohibited functionality.

Nessus

  • NASL familyFreeBSD Local Security Checks
    NASL idFREEBSD_PKG_A250539DD1D44591AFD3C8BDFAC335D8.NASL
    descriptionJenkins Security Advisory : Description(High) SECURITY-1682 / CVE-2020-2099 Inbound TCP Agent Protocol/3 authentication bypass (Medium) SECURITY-1641 / CVE-2020-2100 Jenkins vulnerable to UDP amplification reflection attack (Medium) SECURITY-1659 / CVE-2020-2101 Non-constant time comparison of inbound TCP agent connection secret (Medium) SECURITY-1660 / CVE-2020-2102 Non-constant time HMAC comparison (Medium) SECURITY-1695 / CVE-2020-2103 Diagnostic page exposed session cookies (Medium) SECURITY-1650 / CVE-2020-2104 Memory usage graphs accessible to anyone with Overall/Read (Low) SECURITY-1704 / CVE-2020-2105 Jenkins REST APIs vulnerable to clickjacking (Medium) SECURITY-1680 / CVE-2020-2106 Stored XSS vulnerability in Code Coverage API Plugin (Medium) SECURITY-1565 / CVE-2020-2107 Fortify Plugin stored credentials in plain text (High) SECURITY-1719 / CVE-2020-2108 XXE vulnerability in WebSphere Deployer Plugin
    last seen2020-06-01
    modified2020-06-02
    plugin id133329
    published2020-01-30
    reporterThis script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/133329
    titleFreeBSD : jenkins -- multiple vulnerabilities (a250539d-d1d4-4591-afd3-c8bdfac335d8)
    code
    #
    # (C) Tenable Network Security, Inc.
    #
    # The descriptive text and package checks in this plugin were  
    # extracted from the FreeBSD VuXML database :
    #
    # Copyright 2003-2020 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(133329);
      script_version("1.3");
      script_cvs_date("Date: 2020/02/03");
    
      script_cve_id("CVE-2020-2099", "CVE-2020-2100", "CVE-2020-2101", "CVE-2020-2102", "CVE-2020-2103", "CVE-2020-2104", "CVE-2020-2105", "CVE-2020-2106", "CVE-2020-2107", "CVE-2020-2108");
    
      script_name(english:"FreeBSD : jenkins -- multiple vulnerabilities (a250539d-d1d4-4591-afd3-c8bdfac335d8)");
      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 : Description(High) SECURITY-1682 /
    CVE-2020-2099 Inbound TCP Agent Protocol/3 authentication bypass
    (Medium) SECURITY-1641 / CVE-2020-2100 Jenkins vulnerable to UDP
    amplification reflection attack (Medium) SECURITY-1659 / CVE-2020-2101
    Non-constant time comparison of inbound TCP agent connection secret
    (Medium) SECURITY-1660 / CVE-2020-2102 Non-constant time HMAC
    comparison (Medium) SECURITY-1695 / CVE-2020-2103 Diagnostic page
    exposed session cookies (Medium) SECURITY-1650 / CVE-2020-2104 Memory
    usage graphs accessible to anyone with Overall/Read (Low)
    SECURITY-1704 / CVE-2020-2105 Jenkins REST APIs vulnerable to
    clickjacking (Medium) SECURITY-1680 / CVE-2020-2106 Stored XSS
    vulnerability in Code Coverage API Plugin (Medium) SECURITY-1565 /
    CVE-2020-2107 Fortify Plugin stored credentials in plain text (High)
    SECURITY-1719 / CVE-2020-2108 XXE vulnerability in WebSphere Deployer
    Plugin"
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://jenkins.io/security/advisory/2020-01-29/"
      );
      # https://vuxml.freebsd.org/freebsd/a250539d-d1d4-4591-afd3-c8bdfac335d8.html
      script_set_attribute(
        attribute:"see_also",
        value:"http://www.nessus.org/u?46cd87fc"
      );
      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: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:L/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-2020-2099");
      script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
    
      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:"2020/01/29");
      script_set_attribute(attribute:"patch_publication_date", value:"2020/01/29");
      script_set_attribute(attribute:"plugin_publication_date", value:"2020/01/30");
      script_set_attribute(attribute:"generated_plugin", value:"current");
      script_end_attributes();
    
      script_category(ACT_GATHER_INFO);
      script_copyright(english:"This script is Copyright (C) 2020 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<=2.219")) flag++;
    if (pkg_test(save_report:TRUE, pkg:"jenkins-lts<=2.204.2")) 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");
    
  • NASL familyCGI abuses
    NASL idJENKINS_SECURITY_ADVISORY_2020-01-29.NASL
    descriptionThe version of Jenkins running on the remote web server is prior to 2.219 or is a version of Jenkins LTS prior to 2.204.2. It is, therefore, affected by multiple vulnerabilities: - An UDP amplification reflection attack can be used in a DDoS attack on a Jenkins master. Within the same network, spoofed UDP packets could also be sent to make two Jenkins masters go into an infinite loop of replies to one another, thus causing a denial of service. (CVE-2020-2100) - A non-constant time comparison of inbound TCP agent connection secret is used when an inbound TCP agent connection is initiated. This allows attackers to use statistical methods to obtain the connection secret. (CVE-2020-2101) - A non-constant time HMAC comparison is used when checking whether two HMACs are equal. This could potentially allow attackers to use statistical methods to obtain a valid HMAC for an attacker-controlled input value. (CVE-2020-2102) - User metadata on the /whoAmI page includes the HTTP session ID which allows attackers able to exploit a cross-site scripting vulnerability to obtain the HTTP session ID value. (CVE-2020-2103) - A lack of appropriate permissions allows anyone with Overall/Read permissions to access the JVM memory usage chart for the Jenkins master. (CVE-2020-2104) - The Jenkins REST APIs allows an attacker to perform a clickjacking attack by routing them to a specially crafted web page, and can expose the content of the REST API endpoint. (CVE-2020-2105) Note that Nessus has not tested for these issues but has instead relied only on the application
    last seen2020-04-04
    modified2020-02-06
    plugin id133527
    published2020-02-06
    reporterThis script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/133527
    titleJenkins < 2.204.2 LTS / 2.219 Multiple Vulnerabilities
    code
    #
    # (C) Tenable Network Security, Inc.
    #
    
    include('compat.inc');
    
    if (description)
    {
      script_id(133527);
      script_version("1.3");
      script_set_attribute(attribute:"plugin_modification_date", value:"2020/04/03");
    
      script_cve_id(
        "CVE-2020-2100",
        "CVE-2020-2101",
        "CVE-2020-2102",
        "CVE-2020-2103",
        "CVE-2020-2104",
        "CVE-2020-2105",
        "CVE-2020-2106"
      );
    
      script_name(english:"Jenkins < 2.204.2 LTS / 2.219 Multiple Vulnerabilities");
    
      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
    2.219 or is a version of Jenkins LTS prior to 2.204.2. It is, therefore,
    affected by multiple vulnerabilities:
    
      - An UDP amplification reflection attack can be used in a DDoS attack
        on a Jenkins master. Within the same network, spoofed UDP packets
        could also be sent to make two Jenkins masters go into an infinite
        loop of replies to one another, thus causing a denial of service.
        (CVE-2020-2100)
    
      - A non-constant time comparison of inbound TCP agent connection secret
        is used when an inbound TCP agent connection is initiated. This allows
        attackers to use statistical methods to obtain the connection secret.
        (CVE-2020-2101)
    
      - A non-constant time HMAC comparison is used when checking whether two
        HMACs are equal. This could potentially allow attackers to use
        statistical methods to obtain a valid HMAC for an attacker-controlled
        input value. (CVE-2020-2102)
    
      - User metadata on the /whoAmI page includes the HTTP session ID which
        allows attackers able to exploit a cross-site scripting vulnerability
        to obtain the HTTP session ID value. (CVE-2020-2103)
    
      - A lack of appropriate permissions allows anyone with Overall/Read
        permissions to access the JVM memory usage chart for the Jenkins master.
        (CVE-2020-2104)
    
      - The Jenkins REST APIs allows an attacker to perform a clickjacking
        attack by routing them to a specially crafted web page, and can expose
        the content of the REST API endpoint. (CVE-2020-2105)
    
    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/2020-01-29/");
      script_set_attribute(attribute:"solution", value:
    "Upgrade Jenkins to version 2.219 or later, Jenkins LTS to version 2.204.2 or later.");
      script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:N/I:P/A:N");
      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:R/S:U/C:L/I:L/A:N");
      script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
      script_set_attribute(attribute:"cvss_score_source", value:"CVE-2020-2105");
    
      script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
    
      script_set_attribute(attribute:"vuln_publication_date", value:"2020/01/29");
      script_set_attribute(attribute:"patch_publication_date", value:"2020/01/29");
      script_set_attribute(attribute:"plugin_publication_date", value:"2020/02/06");
    
      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) 2020 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');
    include('vcf.inc');
    
    port = get_http_port(default:8080);
    app = vcf::get_app_info(app:'Jenkins', webapp:TRUE, port:port);
    
    if(app['LTS'])
      constraints = [{'fixed_version' : '2.204.2', 'fixed_display' : '2.204.2 LTS / 2.219'}];
    else
      constraints = [{'fixed_version' : '2.219', 'fixed_display' : '2.204.2 LTS / 2.219'}];
    
    vcf::check_version_and_report(app_info:app, constraints:constraints, severity:SECURITY_WARNING, strict:FALSE);