Vulnerabilities > CVE-2016-6896 - Path Traversal vulnerability in Wordpress 4.5.3

047910
CVSS 5.5 - MEDIUM
Attack vector
NETWORK
Attack complexity
LOW
Privileges required
SINGLE
Confidentiality impact
PARTIAL
Integrity impact
NONE
Availability impact
PARTIAL
network
low complexity
wordpress
CWE-22
nessus
exploit available
metasploit
NVD
Published: 2017-01-18
Updated: 2017-09-03

Summary

Directory traversal vulnerability in the wp_ajax_update_plugin function in wp-admin/includes/ajax-actions.php in WordPress 4.5.3 allows remote authenticated users to cause a denial of service or read certain text files via a .. (dot dot) in the plugin parameter to wp-admin/admin-ajax.php, as demonstrated by /dev/random read operations that deplete the entropy pool.

Vulnerable Configurations

Part Description Count
Application
Wordpress
1

Common Weakness Enumeration (CWE)

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.

Exploit-Db

descriptionWordPress 4.5.3 - Directory Traversal / Denial of Service. CVE-2016-6896,CVE-2016-6897. Webapps exploit for PHP platform
fileexploits/php/webapps/40288.txt
idEDB-ID:40288
last seen2016-08-22
modified2016-08-22
platformphp
port80
published2016-08-22
reporterYorick Koster
titleWordPress 4.5.3 - Directory Traversal / Denial of Service
typewebapps

Metasploit

descriptionCross-site request forgery (CSRF) vulnerability in the wp_ajax_update_plugin function in wp-admin/includes/ajax-actions.php in WordPress before 4.6 allows remote attackers to hijack the authentication of subscribers for /dev/random read operations by leveraging a late call to the check_ajax_referer function, a related issue to CVE-2016-6896.
idMSF:AUXILIARY/DOS/HTTP/WORDPRESS_DIRECTORY_TRAVERSAL_DOS
last seen2020-01-06
modified2017-07-24
published2017-04-30
referenceshttps://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-6897
reporterRapid7
sourcehttps://github.com/rapid7/metasploit-framework/blob/master//modules/auxiliary/dos/http/wordpress_directory_traversal_dos.rb
titleWordPress Traversal Directory DoS

Nessus

  • NASL familyFedora Local Security Checks
    NASL idFEDORA_2016-A8657278BF.NASL
    descriptionSee upstream announcements : - [WordPress 4.6 “Pepper”](https://wordpress.org/news/2016/08 /pepper/) - [WordPress 4.6.1 Security and Maintenance Release](https://wordpress.org/news/2016/09/wordpress-4- 6-1-security-and-maintenance-release/) Note that Tenable Network Security has extracted the preceding description block directly from the Fedora update system website. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
    last seen2020-06-05
    modified2016-09-22
    plugin id93633
    published2016-09-22
    reporterThis script is Copyright (C) 2016-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/93633
    titleFedora 24 : wordpress (2016-a8657278bf)
    code
    #%NASL_MIN_LEVEL 80502
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were  
# extracted from Fedora Security Advisory FEDORA-2016-a8657278bf.
#

include("compat.inc");

if (description)
{
  script_id(93633);
  script_version("2.12");
  script_set_attribute(attribute:"plugin_modification_date", value:"2020/06/04");

  script_cve_id("CVE-2016-6896", "CVE-2016-7168");
  script_xref(name:"FEDORA", value:"2016-a8657278bf");

  script_name(english:"Fedora 24 : wordpress (2016-a8657278bf)");
  script_summary(english:"Checks rpm output for the updated package.");

  script_set_attribute(
    attribute:"synopsis", 
    value:"The remote Fedora host is missing a security update."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"See upstream announcements :

  - [WordPress 4.6
    “Pepper”](https://wordpress.org/news/2016/08
    /pepper/)

  - [WordPress 4.6.1 Security and Maintenance
    Release](https://wordpress.org/news/2016/09/wordpress-4-
    6-1-security-and-maintenance-release/)

Note that Tenable Network Security has extracted the preceding
description block directly from the Fedora update system website.
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://bodhi.fedoraproject.org/updates/FEDORA-2016-a8657278bf"
  );
  script_set_attribute(
    attribute:"solution", 
    value:"Update the affected wordpress package."
  );
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:S/C:P/I:N/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:L/UI:N/S:U/C:L/I:N/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:fedoraproject:fedora:wordpress");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:fedoraproject:fedora:24");

  script_set_attribute(attribute:"vuln_publication_date", value:"2017/01/05");
  script_set_attribute(attribute:"patch_publication_date", value:"2016/09/21");
  script_set_attribute(attribute:"plugin_publication_date", value:"2016/09/22");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2016-2020 and is owned by Tenable, Inc. or an Affiliate thereof.");
  script_family(english:"Fedora Local Security Checks");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/RedHat/release", "Host/RedHat/rpm-list");

  exit(0);
}


include("audit.inc");
include("global_settings.inc");
include("rpm.inc");


if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
release = get_kb_item("Host/RedHat/release");
if (isnull(release) || "Fedora" >!< release) audit(AUDIT_OS_NOT, "Fedora");
os_ver = pregmatch(pattern: "Fedora.*release ([0-9]+)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "Fedora");
os_ver = os_ver[1];
if (! preg(pattern:"^24([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, "Fedora 24", "Fedora " + os_ver);

if (!get_kb_item("Host/RedHat/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING);


cpu = get_kb_item("Host/cpu");
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ("x86_64" >!< cpu && cpu !~ "^i[3-6]86$") audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "Fedora", cpu);


flag = 0;
if (rpm_check(release:"FC24", reference:"wordpress-4.6.1-1.fc24")) flag++;


if (flag)
{
  security_report_v4(
    port       : 0,
    severity   : SECURITY_WARNING,
    extra      : rpm_report_get()
  );
  exit(0);
}
else
{
  tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "wordpress");
}
  • NASL familyFedora Local Security Checks
    NASL idFEDORA_2016-91BFE9DDB8.NASL
    descriptionSee upstream announcements : - [WordPress 4.6 &ldquo;Pepper&rdquo;](https://wordpress.org/news/2016/08 /pepper/) - [WordPress 4.6.1 Security and Maintenance Release](https://wordpress.org/news/2016/09/wordpress-4- 6-1-security-and-maintenance-release/) Note that Tenable Network Security has extracted the preceding description block directly from the Fedora update system website. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
    last seen2020-06-05
    modified2016-09-22
    plugin id93630
    published2016-09-22
    reporterThis script is Copyright (C) 2016-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/93630
    titleFedora 23 : wordpress (2016-91bfe9ddb8)
    code
    #%NASL_MIN_LEVEL 80502
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were  
# extracted from Fedora Security Advisory FEDORA-2016-91bfe9ddb8.
#

include("compat.inc");

if (description)
{
  script_id(93630);
  script_version("2.12");
  script_set_attribute(attribute:"plugin_modification_date", value:"2020/06/04");

  script_cve_id("CVE-2016-6896", "CVE-2016-7168");
  script_xref(name:"FEDORA", value:"2016-91bfe9ddb8");

  script_name(english:"Fedora 23 : wordpress (2016-91bfe9ddb8)");
  script_summary(english:"Checks rpm output for the updated package.");

  script_set_attribute(
    attribute:"synopsis", 
    value:"The remote Fedora host is missing a security update."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"See upstream announcements :

  - [WordPress 4.6
    &ldquo;Pepper&rdquo;](https://wordpress.org/news/2016/08
    /pepper/)

  - [WordPress 4.6.1 Security and Maintenance
    Release](https://wordpress.org/news/2016/09/wordpress-4-
    6-1-security-and-maintenance-release/)

Note that Tenable Network Security has extracted the preceding
description block directly from the Fedora update system website.
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://bodhi.fedoraproject.org/updates/FEDORA-2016-91bfe9ddb8"
  );
  script_set_attribute(
    attribute:"solution", 
    value:"Update the affected wordpress package."
  );
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:S/C:P/I:N/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:L/UI:N/S:U/C:L/I:N/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:fedoraproject:fedora:wordpress");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:fedoraproject:fedora:23");

  script_set_attribute(attribute:"vuln_publication_date", value:"2017/01/05");
  script_set_attribute(attribute:"patch_publication_date", value:"2016/09/21");
  script_set_attribute(attribute:"plugin_publication_date", value:"2016/09/22");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2016-2020 and is owned by Tenable, Inc. or an Affiliate thereof.");
  script_family(english:"Fedora Local Security Checks");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/RedHat/release", "Host/RedHat/rpm-list");

  exit(0);
}


include("audit.inc");
include("global_settings.inc");
include("rpm.inc");


if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
release = get_kb_item("Host/RedHat/release");
if (isnull(release) || "Fedora" >!< release) audit(AUDIT_OS_NOT, "Fedora");
os_ver = pregmatch(pattern: "Fedora.*release ([0-9]+)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "Fedora");
os_ver = os_ver[1];
if (! preg(pattern:"^23([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, "Fedora 23", "Fedora " + os_ver);

if (!get_kb_item("Host/RedHat/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING);


cpu = get_kb_item("Host/cpu");
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ("x86_64" >!< cpu && cpu !~ "^i[3-6]86$") audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "Fedora", cpu);


flag = 0;
if (rpm_check(release:"FC23", reference:"wordpress-4.6.1-1.fc23")) flag++;


if (flag)
{
  security_report_v4(
    port       : 0,
    severity   : SECURITY_WARNING,
    extra      : rpm_report_get()
  );
  exit(0);
}
else
{
  tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "wordpress");
}
  • NASL familyFedora Local Security Checks
    NASL idFEDORA_2016-80A1D6211A.NASL
    descriptionSee upstream announcement: [WordPress 4.6 &ldquo;Pepper&rdquo;](https://wordpress.org/news/2016/08/pepper/) Note that Tenable Network Security has extracted the preceding description block directly from the Fedora update system website. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
    last seen2020-06-05
    modified2016-11-15
    plugin id94825
    published2016-11-15
    reporterThis script is Copyright (C) 2016-2020 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/94825
    titleFedora 25 : wordpress (2016-80a1d6211a)
  • NASL familyCGI abuses
    NASL idWORDPRESS_4_6.NASL
    descriptionAccording to its self-reported version number, the WordPress application running on the remote web server is prior to 4.6. It is, therefore, affected by multiple vulnerabilities : - A path traversal vulnerability exists in the WordPress Admin API in the wp_ajax_update_plugin() function in ajax-actions.php due to improper sanitization of user-supplied input. An authenticated, remote attacker can exploit this, via a specially crafted request, to cause a denial of service condition. (CVE-2016-6896) - A cross-site request forgery vulnerability (XSRF) exists in the admin-ajax.php script 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 this, by convincing a user to follow a specially crafted link, to perform arbitrary AJAX updates. (CVE-2016-6897) - An information disclosure vulnerability exists in the wp_ajax_update_plugin() function in the ajax-actions.php script due to performing a call to get_plug_data() before checking capabilities. An authenticated, remote attacker can exploit this to bypass intended read-access restrictions, resulting in a disclosure of sensitive information. (CVE-2016-10148) 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 id93111
    published2016-08-25
    reporterThis script is Copyright (C) 2016-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/93111
    titleWordPress < 4.6 Multiple Vulnerabilities

References