CVE-2020-11026 - Cross-Site Scripting vulnerability in Wordpress

047910
CVSS 3.5 - LOW
Attack vector
NETWORK
Attack complexity
MEDIUM
Privileges required
SINGLE
Confidentiality impact
NONE
Integrity impact
PARTIAL
Availability impact
NONE
network
wordpress
debian
CWE-79
nessus

Summary

In affected versions of WordPress, files with a specially crafted name when uploaded to the Media section can lead to script execution upon accessing the file. This requires an authenticated user with privileges to upload files. This has been patched in version 5.4.1, along with all the previously affected versions via a minor release (5.3.3, 5.2.6, 5.1.5, 5.0.9, 4.9.14, 4.8.13, 4.7.17, 4.6.18, 4.5.21, 4.4.22, 4.3.23, 4.2.27, 4.1.30, 4.0.30, 3.9.31, 3.8.33, 3.7.33).

Vulnerable 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 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-2208.NASL
    descriptionMultiple CVE(s) were discovered in the src:wordpress package. CVE-2020-11026 Files with a specially crafted name when uploaded to the Media section can lead to script execution upon accessing the file. This requires an authenticated user with privileges to upload files. CVE-2020-11027 A password reset link emailed to a user does not expire upon changing the user password. Access would be needed to the email account of the user by a malicious party for successful execution. CVE-2020-11028 Some private posts, which were previously public, can result in unauthenticated disclosure under a specific set of conditions. CVE-2020-11029 A vulnerability in the stats() method of class-wp-object-cache.php can be exploited to execute cross-site scripting (XSS) attacks. For Debian 8
    last seen2020-05-15
    modified2020-05-12
    plugin id136484
    published2020-05-12
    reporterThis script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/136484
    titleDebian DLA-2208-1 : 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-2208-1. The text
    # itself is copyright (C) Software in the Public Interest, Inc.
    #
    
    include("compat.inc");
    
    if (description)
    {
      script_id(136484);
      script_version("1.4");
      script_set_attribute(attribute:"plugin_modification_date", value:"2020/06/19");
    
      script_cve_id("CVE-2020-11026", "CVE-2020-11027", "CVE-2020-11028", "CVE-2020-11029");
      script_xref(name:"IAVA", value:"2020-A-0191-S");
    
      script_name(english:"Debian DLA-2208-1 : 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:
    "Multiple CVE(s) were discovered in the src:wordpress package.
    
    CVE-2020-11026
    
    Files with a specially crafted name when uploaded to the Media section
    can lead to script execution upon accessing the file. This requires an
    authenticated user with privileges to upload files.
    
    CVE-2020-11027
    
    A password reset link emailed to a user does not expire upon changing
    the user password. Access would be needed to the email account of the
    user by a malicious party for successful execution.
    
    CVE-2020-11028
    
    Some private posts, which were previously public, can result in
    unauthenticated disclosure under a specific set of conditions.
    
    CVE-2020-11029
    
    A vulnerability in the stats() method of class-wp-object-cache.php can
    be exploited to execute cross-site scripting (XSS) attacks.
    
    For Debian 8 'Jessie', these problems have been fixed in version
    4.1.30+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/2020/05/msg00011.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:S/C:P/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:L/UI:N/S:U/C:H/I:H/A:N");
      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:"2020/04/30");
      script_set_attribute(attribute:"patch_publication_date", value:"2020/05/11");
      script_set_attribute(attribute:"plugin_publication_date", value:"2020/05/12");
      script_set_attribute(attribute:"stig_severity", value:"II");
      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:"4.1.30+dfsg-0+deb8u1")) flag++;
    if (deb_check(release:"8.0", prefix:"wordpress-l10n", reference:"4.1.30+dfsg-0+deb8u1")) flag++;
    if (deb_check(release:"8.0", prefix:"wordpress-theme-twentyfifteen", reference:"4.1.30+dfsg-0+deb8u1")) flag++;
    if (deb_check(release:"8.0", prefix:"wordpress-theme-twentyfourteen", reference:"4.1.30+dfsg-0+deb8u1")) flag++;
    if (deb_check(release:"8.0", prefix:"wordpress-theme-twentythirteen", reference:"4.1.30+dfsg-0+deb8u1")) flag++;
    
    if (flag)
    {
      if (report_verbosity > 0) security_warning(port:0, extra:deb_report_get());
      else security_warning(0);
      exit(0);
    }
    else audit(AUDIT_HOST_NOT, "affected");