CVE-2019-20041 - Improper Input Validation vulnerability in Wordpress

047910
CVSS 7.5 - HIGH
Attack vector
NETWORK
Attack complexity
LOW
Privileges required
NONE
Confidentiality impact
PARTIAL
Integrity impact
PARTIAL
Availability impact
PARTIAL
network
low complexity
wordpress
CWE-20
nessus

Summary

wp_kses_bad_protocol in wp-includes/kses.php in WordPress before 5.3.1 mishandles the HTML5 colon named entity, allowing attackers to bypass input sanitization, as demonstrated by the javascript: substring.

Vulnerable Configurations

Common Weakness Enumeration (CWE)

CWE-20 - Improper Input Validation

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Buffer Overflow via Environment Variables
    This attack pattern involves causing a buffer overflow through manipulation of environment variables. Once the attacker finds that they can modify an environment variable, they may try to overflow associated buffers. This attack leverages implicit trust often placed in environment variables.
  • Server Side Include (SSI) Injection
    An attacker can use Server Side Include (SSI) Injection to send code to a web application that then gets executed by the web server. Doing so enables the attacker to achieve similar results to Cross Site Scripting, viz., arbitrary code execution and information disclosure, albeit on a more limited scale, since the SSI directives are nowhere near as powerful as a full-fledged scripting language. Nonetheless, the attacker can conveniently gain access to sensitive files, such as password files, and execute shell commands.
  • Cross Zone Scripting
    An attacker is able to cause a victim to load content into their web-browser that bypasses security zone controls and gain access to increased privileges to execute scripting code or other web objects such as unsigned ActiveX controls or applets. This is a privilege elevation attack targeted at zone-based web-browser security. In a zone-based model, pages belong to one of a set of zones corresponding to the level of privilege assigned to that page. Pages in an untrusted zone would have a lesser level of access to the system and/or be restricted in the types of executable content it was allowed to invoke. In a cross-zone scripting attack, a page that should be assigned to a less privileged zone is granted the privileges of a more trusted zone. This can be accomplished by exploiting bugs in the browser, exploiting incorrect configuration in the zone controls, through a cross-site scripting attack that causes the attackers' content to be treated as coming from a more trusted page, or by leveraging some piece of system functionality that is accessible from both the trusted and less trusted zone. This attack differs from "Restful Privilege Escalation" in that the latter correlates to the inadequate securing of RESTful access methods (such as HTTP DELETE) on the server, while cross-zone scripting attacks the concept of security zones as implemented by a browser.
  • 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.
  • Command Line Execution through SQL Injection
    An attacker uses standard SQL injection methods to inject data into the command line for execution. This could be done directly through misuse of directives such as MSSQL_xp_cmdshell or indirectly through injection of data into the database that would be interpreted as shell commands. Sometime later, an unscrupulous backend application (or could be part of the functionality of the same application) fetches the injected data stored in the database and uses this data as command line arguments without performing proper validation. The malicious data escapes that data plane by spawning new commands to be executed on the host.

Nessus

  • NASL familyDebian Local Security Checks
    NASL idDEBIAN_DSA-4677.NASL
    descriptionSeveral vulnerabilities were discovered in Wordpress, a web blogging tool. They allowed remote attackers to perform various Cross-Side Scripting (XSS) and Cross-Site Request Forgery (CSRF) attacks, create files on the server, disclose private information, create open redirects, poison cache, and bypass authorization access and input sanitation.
    last seen2020-05-12
    modified2020-05-07
    plugin id136373
    published2020-05-07
    reporterThis script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/136373
    titleDebian DSA-4677-1 : wordpress - security update
    code
    #
    # (C) Tenable Network Security, Inc.
    #
    # The descriptive text and package checks in this plugin were  
    # extracted from Debian Security Advisory DSA-4677. The text 
    # itself is copyright (C) Software in the Public Interest, Inc.
    #
    
    include("compat.inc");
    
    if (description)
    {
      script_id(136373);
      script_version("1.4");
      script_set_attribute(attribute:"plugin_modification_date", value:"2020/06/19");
    
      script_cve_id("CVE-2019-16217", "CVE-2019-16218", "CVE-2019-16219", "CVE-2019-16220", "CVE-2019-16221", "CVE-2019-16222", "CVE-2019-16223", "CVE-2019-16780", "CVE-2019-16781", "CVE-2019-17669", "CVE-2019-17671", "CVE-2019-17672", "CVE-2019-17673", "CVE-2019-17674", "CVE-2019-17675", "CVE-2019-20041", "CVE-2019-20042", "CVE-2019-20043", "CVE-2019-9787", "CVE-2020-11025", "CVE-2020-11026", "CVE-2020-11027", "CVE-2020-11028", "CVE-2020-11029", "CVE-2020-11030");
      script_xref(name:"DSA", value:"4677");
      script_xref(name:"IAVA", value:"2020-A-0191-S");
    
      script_name(english:"Debian DSA-4677-1 : wordpress - security update");
      script_summary(english:"Checks dpkg output for the updated package");
    
      script_set_attribute(
        attribute:"synopsis", 
        value:"The remote Debian host is missing a security-related update."
      );
      script_set_attribute(
        attribute:"description", 
        value:
    "Several vulnerabilities were discovered in Wordpress, a web blogging
    tool. They allowed remote attackers to perform various Cross-Side
    Scripting (XSS) and Cross-Site Request Forgery (CSRF) attacks, create
    files on the server, disclose private information, create open
    redirects, poison cache, and bypass authorization access and input
    sanitation."
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=924546"
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=939543"
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=942459"
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=946905"
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=959391"
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://security-tracker.debian.org/tracker/source-package/wordpress"
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://packages.debian.org/source/stretch/wordpress"
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://packages.debian.org/source/buster/wordpress"
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://www.debian.org/security/2020/dsa-4677"
      );
      script_set_attribute(
        attribute:"solution", 
        value:
    "Upgrade the wordpress packages.
    
    For the oldstable distribution (stretch), these problems have been
    fixed in version 4.7.5+dfsg-2+deb9u6.
    
    For the stable distribution (buster), these problems have been fixed
    in version 5.0.4+dfsg1-1+deb10u2."
      );
      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:debian:debian_linux:wordpress");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:10.0");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:9.0");
    
      script_set_attribute(attribute:"vuln_publication_date", value:"2019/03/14");
      script_set_attribute(attribute:"patch_publication_date", value:"2020/05/06");
      script_set_attribute(attribute:"plugin_publication_date", value:"2020/05/07");
      script_set_attribute(attribute:"generated_plugin", value:"current");
      script_set_attribute(attribute:"stig_severity", value:"II");
      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:"Debian Local Security Checks");
    
      script_dependencies("ssh_get_info.nasl");
      script_require_keys("Host/local_checks_enabled", "Host/Debian/release", "Host/Debian/dpkg-l");
    
      exit(0);
    }
    
    
    include("audit.inc");
    include("debian_package.inc");
    
    
    if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
    if (!get_kb_item("Host/Debian/release")) audit(AUDIT_OS_NOT, "Debian");
    if (!get_kb_item("Host/Debian/dpkg-l")) audit(AUDIT_PACKAGE_LIST_MISSING);
    
    
    flag = 0;
    if (deb_check(release:"10.0", prefix:"wordpress", reference:"5.0.4+dfsg1-1+deb10u2")) flag++;
    if (deb_check(release:"10.0", prefix:"wordpress-l10n", reference:"5.0.4+dfsg1-1+deb10u2")) flag++;
    if (deb_check(release:"10.0", prefix:"wordpress-theme-twentynineteen", reference:"5.0.4+dfsg1-1+deb10u2")) flag++;
    if (deb_check(release:"10.0", prefix:"wordpress-theme-twentyseventeen", reference:"5.0.4+dfsg1-1+deb10u2")) flag++;
    if (deb_check(release:"10.0", prefix:"wordpress-theme-twentysixteen", reference:"5.0.4+dfsg1-1+deb10u2")) flag++;
    if (deb_check(release:"9.0", prefix:"wordpress", reference:"4.7.5+dfsg-2+deb9u6")) flag++;
    if (deb_check(release:"9.0", prefix:"wordpress-l10n", reference:"4.7.5+dfsg-2+deb9u6")) flag++;
    if (deb_check(release:"9.0", prefix:"wordpress-theme-twentyfifteen", reference:"4.7.5+dfsg-2+deb9u6")) flag++;
    if (deb_check(release:"9.0", prefix:"wordpress-theme-twentyseventeen", reference:"4.7.5+dfsg-2+deb9u6")) flag++;
    if (deb_check(release:"9.0", prefix:"wordpress-theme-twentysixteen", reference:"4.7.5+dfsg-2+deb9u6")) flag++;
    
    if (flag)
    {
      if (report_verbosity > 0) security_hole(port:0, extra:deb_report_get());
      else security_hole(0);
      exit(0);
    }
    else audit(AUDIT_HOST_NOT, "affected");
    
  • NASL familyDebian Local Security Checks
    NASL idDEBIAN_DLA-2067.NASL
    descriptionAn input sanitization bypass was discovered in Wordpress, a popular content management framework. An attacker can use this flaw to send malicious scripts to an unsuspecting user. For Debian 8
    last seen2020-06-01
    modified2020-06-02
    plugin id132874
    published2020-01-15
    reporterThis script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/132874
    titleDebian DLA-2067-1 : wordpress security update
    code
    #
    # (C) Tenable Network Security, Inc.
    #
    # The descriptive text and package checks in this plugin were
    # extracted from Debian Security Advisory DLA-2067-1. The text
    # itself is copyright (C) Software in the Public Interest, Inc.
    #
    
    include("compat.inc");
    
    if (description)
    {
      script_id(132874);
      script_version("1.2");
      script_cvs_date("Date: 2020/01/17");
    
      script_cve_id("CVE-2019-20041");
    
      script_name(english:"Debian DLA-2067-1 : wordpress security update");
      script_summary(english:"Checks dpkg output for the updated packages.");
    
      script_set_attribute(
        attribute:"synopsis", 
        value:"The remote Debian host is missing a security update."
      );
      script_set_attribute(
        attribute:"description", 
        value:
    "An input sanitization bypass was discovered in Wordpress, a popular
    content management framework. An attacker can use this flaw to send
    malicious scripts to an unsuspecting user.
    
    For Debian 8 'Jessie', this problem has been fixed in version
    4.1.29+dfsg-0+deb8u1.
    
    We recommend that you upgrade your wordpress packages.
    
    NOTE: Tenable Network Security has extracted the preceding description
    block directly from the DLA security advisory. Tenable has attempted
    to automatically clean and format it as much as possible without
    introducing additional issues."
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://lists.debian.org/debian-lts-announce/2020/01/msg00010.html"
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://packages.debian.org/source/jessie/wordpress"
      );
      script_set_attribute(attribute:"solution", value:"Upgrade 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:H/A:H");
      script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
      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:debian:debian_linux:wordpress");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:wordpress-l10n");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:wordpress-theme-twentyfifteen");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:wordpress-theme-twentyfourteen");
      script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:wordpress-theme-twentythirteen");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:8.0");
    
      script_set_attribute(attribute:"vuln_publication_date", value:"2019/12/27");
      script_set_attribute(attribute:"patch_publication_date", value:"2020/01/14");
      script_set_attribute(attribute:"plugin_publication_date", value:"2020/01/15");
      script_set_attribute(attribute:"generated_plugin", value:"current");
      script_end_attributes();
    
      script_category(ACT_GATHER_INFO);
      script_copyright(english:"This script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof.");
      script_family(english:"Debian Local Security Checks");
    
      script_dependencies("ssh_get_info.nasl");
      script_require_keys("Host/local_checks_enabled", "Host/Debian/release", "Host/Debian/dpkg-l");
    
      exit(0);
    }
    
    
    include("audit.inc");
    include("debian_package.inc");
    
    
    if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
    if (!get_kb_item("Host/Debian/release")) audit(AUDIT_OS_NOT, "Debian");
    if (!get_kb_item("Host/Debian/dpkg-l")) audit(AUDIT_PACKAGE_LIST_MISSING);
    
    
    flag = 0;
    if (deb_check(release:"8.0", prefix:"wordpress", reference:"4.1.29+dfsg-0+deb8u1")) flag++;
    if (deb_check(release:"8.0", prefix:"wordpress-l10n", reference:"4.1.29+dfsg-0+deb8u1")) flag++;
    if (deb_check(release:"8.0", prefix:"wordpress-theme-twentyfifteen", reference:"4.1.29+dfsg-0+deb8u1")) flag++;
    if (deb_check(release:"8.0", prefix:"wordpress-theme-twentyfourteen", reference:"4.1.29+dfsg-0+deb8u1")) flag++;
    if (deb_check(release:"8.0", prefix:"wordpress-theme-twentythirteen", reference:"4.1.29+dfsg-0+deb8u1")) flag++;
    
    if (flag)
    {
      if (report_verbosity > 0) security_hole(port:0, extra:deb_report_get());
      else security_hole(0);
      exit(0);
    }
    else audit(AUDIT_HOST_NOT, "affected");
    
  • NASL familyDebian Local Security Checks
    NASL idDEBIAN_DSA-4599.NASL
    descriptionSeveral vulnerabilities were discovered in Wordpress, a web blogging tool. They allowed remote attackers to perform various Cross-Side Scripting (XSS) and Cross-Site Request Forgery (CSRF) attacks, create open redirects, poison cache, and bypass authorization access and input sanitation.
    last seen2020-06-01
    modified2020-06-02
    plugin id132736
    published2020-01-09
    reporterThis script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/132736
    titleDebian DSA-4599-1 : wordpress - security update
    code
    #
    # (C) Tenable Network Security, Inc.
    #
    # The descriptive text and package checks in this plugin were  
    # extracted from Debian Security Advisory DSA-4599. The text 
    # itself is copyright (C) Software in the Public Interest, Inc.
    #
    
    include("compat.inc");
    
    if (description)
    {
      script_id(132736);
      script_version("1.2");
      script_cvs_date("Date: 2020/01/13");
    
      script_cve_id("CVE-2019-16217", "CVE-2019-16218", "CVE-2019-16219", "CVE-2019-16220", "CVE-2019-16221", "CVE-2019-16222", "CVE-2019-16223", "CVE-2019-16780", "CVE-2019-16781", "CVE-2019-17669", "CVE-2019-17671", "CVE-2019-17672", "CVE-2019-17673", "CVE-2019-17674", "CVE-2019-17675", "CVE-2019-20041", "CVE-2019-20042", "CVE-2019-20043");
      script_xref(name:"DSA", value:"4599");
    
      script_name(english:"Debian DSA-4599-1 : wordpress - security update");
      script_summary(english:"Checks dpkg output for the updated package");
    
      script_set_attribute(
        attribute:"synopsis", 
        value:"The remote Debian host is missing a security-related update."
      );
      script_set_attribute(
        attribute:"description", 
        value:
    "Several vulnerabilities were discovered in Wordpress, a web blogging
    tool. They allowed remote attackers to perform various Cross-Side
    Scripting (XSS) and Cross-Site Request Forgery (CSRF) attacks, create
    open redirects, poison cache, and bypass authorization access and
    input sanitation."
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=939543"
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=942459"
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=946905"
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://security-tracker.debian.org/tracker/source-package/wordpress"
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://packages.debian.org/source/buster/wordpress"
      );
      script_set_attribute(
        attribute:"see_also",
        value:"https://www.debian.org/security/2020/dsa-4599"
      );
      script_set_attribute(
        attribute:"solution", 
        value:
    "Upgrade the wordpress packages.
    
    For the stable distribution (buster), these problems have been fixed
    in version 5.0.4+dfsg1-1+deb10u1."
      );
      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:debian:debian_linux:wordpress");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:10.0");
    
      script_set_attribute(attribute:"vuln_publication_date", value:"2019/09/11");
      script_set_attribute(attribute:"patch_publication_date", value:"2020/01/08");
      script_set_attribute(attribute:"plugin_publication_date", value:"2020/01/09");
      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:"Debian Local Security Checks");
    
      script_dependencies("ssh_get_info.nasl");
      script_require_keys("Host/local_checks_enabled", "Host/Debian/release", "Host/Debian/dpkg-l");
    
      exit(0);
    }
    
    
    include("audit.inc");
    include("debian_package.inc");
    
    
    if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
    if (!get_kb_item("Host/Debian/release")) audit(AUDIT_OS_NOT, "Debian");
    if (!get_kb_item("Host/Debian/dpkg-l")) audit(AUDIT_PACKAGE_LIST_MISSING);
    
    
    flag = 0;
    if (deb_check(release:"10.0", prefix:"wordpress", reference:"5.0.4+dfsg1-1+deb10u1")) flag++;
    if (deb_check(release:"10.0", prefix:"wordpress-l10n", reference:"5.0.4+dfsg1-1+deb10u1")) flag++;
    if (deb_check(release:"10.0", prefix:"wordpress-theme-twentynineteen", reference:"5.0.4+dfsg1-1+deb10u1")) flag++;
    if (deb_check(release:"10.0", prefix:"wordpress-theme-twentyseventeen", reference:"5.0.4+dfsg1-1+deb10u1")) flag++;
    if (deb_check(release:"10.0", prefix:"wordpress-theme-twentysixteen", reference:"5.0.4+dfsg1-1+deb10u1")) flag++;
    
    if (flag)
    {
      if (report_verbosity > 0) security_hole(port:0, extra:deb_report_get());
      else security_hole(0);
      exit(0);
    }
    else audit(AUDIT_HOST_NOT, "affected");