Vulnerabilities > CVE-2019-8943 - Path Traversal vulnerability in Wordpress

047910
CVSS 6.5 - MEDIUM
Attack vector
NETWORK
Attack complexity
LOW
Privileges required
LOW
Confidentiality impact
NONE
Integrity impact
HIGH
Availability impact
NONE
network
low complexity
wordpress
CWE-22
nessus
exploit available
metasploit
NVD
Published: 2019-02-20
Updated: 2024-11-21

Summary

WordPress through 5.0.3 allows Path Traversal in wp_crop_image(). An attacker (who has privileges to crop an image) can write the output image to an arbitrary directory via a filename containing two image extensions and ../ sequences, such as a filename ending with the .jpg?/../../file.jpg substring.

Vulnerable Configurations

Part Description Count
Application
Wordpress
846

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

  • fileexploits/php/remote/46662.rb
    idEDB-ID:46662
    last seen2019-04-05
    modified2019-04-05
    platformphp
    port80
    published2019-04-05
    reporterExploit-DB
    sourcehttps://www.exploit-db.com/download/46662
    titleWordPress 5.0.0 - Crop-image Shell Upload (Metasploit)
    typeremote
  • fileexploits/php/webapps/46511.js
    idEDB-ID:46511
    last seen2019-03-07
    modified2019-03-01
    platformphp
    port
    published2019-03-01
    reporterExploit-DB
    sourcehttps://www.exploit-db.com/download/46511
    titleWordPress Core 5.0 - Remote Code Execution
    typewebapps

Metasploit

descriptionThis module exploits a path traversal and a local file inclusion vulnerability on WordPress versions 5.0.0 and <= 4.9.8. The crop-image function allows a user, with at least author privileges, to resize an image and perform a path traversal by changing the _wp_attached_file reference during the upload. The second part of the exploit will include this image in the current theme by changing the _wp_page_template attribute when creating a post. This exploit module only works for Unix-based systems currently.
idMSF:EXPLOIT/MULTI/HTTP/WP_CROP_RCE
last seen2020-06-13
modified2019-04-04
published2019-03-22
references
reporterRapid7
sourcehttps://github.com/rapid7/metasploit-framework/blob/master//modules/exploits/multi/http/wp_crop_rce.rb
titleWordPress Crop-image Shell Upload

Nessus

NASL familyCGI abuses
NASL idWORDPRESS_5_0_4.NASL
descriptionAccording to its self-reported version number, the WordPress application running on the remote web server is prior to 5.0.4. It is, therefore, affected by a directory traversal vulnerability in its wp_crop_image() component. An authenticated, remote attacker can exploit this, by sending a URI that contains directory traversal characters, to disclose the contents of files located outside of the server
last seen2020-06-01
modified2020-06-02
plugin id125596
published2019-05-30
reporterThis script is Copyright (C) 2019 and is owned by Tenable, Inc. or an Affiliate thereof.
sourcehttps://www.tenable.com/plugins/nessus/125596
titleWordPress < 5.0.4 Directory Traversal Vulnerability
code
#
# (C) Tenable Network Security, Inc.
#
include('compat.inc');

if (description)
{
  script_id(125596);
  script_version("1.3");
  script_cvs_date("Date: 2019/06/04  9:45:00");

  script_cve_id("CVE-2019-8943");
  script_bugtraq_id(107089);

  script_name(english:"WordPress < 5.0.4 Directory Traversal Vulnerability");
  script_summary(english:"Checks the version of WordPress.");

  script_set_attribute(attribute:"synopsis", value:
"A PHP application running on the remote web server is affected by a directory traversal vulnerability.");
  script_set_attribute(attribute:"description", value:
"According to its self-reported version number, the WordPress application running on the remote web server is prior to 
5.0.4. It is, therefore, affected by a directory traversal vulnerability in its wp_crop_image() component. 
An authenticated, remote attacker can exploit this, by sending a URI that contains directory traversal characters, to 
disclose the contents of files located outside of the server's restricted path.");
  # https://wordpress.org/support/wordpress-version/version-5-0-4
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?70233294");
  script_set_attribute(attribute:"solution", value:"Upgrade to WordPress version 5.0.4 or later.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:S/C:N/I:P/A:N");
  script_set_cvss_temporal_vector("CVSS2#E:F/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:F/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2019-8943");
  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");
  script_set_attribute(attribute:"metasploit_name", value:'WordPress Crop-image Shell Upload');
  script_set_attribute(attribute:"exploit_framework_metasploit", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2019/02/19");
  script_set_attribute(attribute:"patch_publication_date", value:"2019/03/13");
  script_set_attribute(attribute:"plugin_publication_date", value:"2019/05/30");

  script_set_attribute(attribute:"plugin_type", value:"remote");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:wordpress:wordpress");
  script_set_attribute(attribute:"potential_vulnerability", value:"true");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"CGI abuses");

  script_copyright(english:"This script is Copyright (C) 2019 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("wordpress_detect.nasl");
  script_require_keys("www/PHP", "installed_sw/WordPress", "Settings/ParanoidReport");
  script_require_ports("Services/www", 80, 443);

  exit(0);
}

include('vcf.inc');
include('http.inc');

if (report_paranoia < 2) audit(AUDIT_PARANOID);

port = get_http_port(default:80, php:TRUE);
app_info = vcf::get_app_info(app:'WordPress', port:port, webapp:TRUE);

constraints = [{'fixed_version':'5.0.4' }];
vcf::check_version_and_report(app_info:app_info, constraints:constraints, severity:SECURITY_WARNING);

Packetstorm

data sourcehttps://packetstormsecurity.com/files/download/152396/wp_crop_rce.rb.txt
idPACKETSTORM:152396
last seen2019-04-05
published2019-04-04
reporterRIPSTECH Technology
sourcehttps://packetstormsecurity.com/files/152396/WordPress-5.0.0-crop-image-Shell-Upload.html
titleWordPress 5.0.0 crop-image Shell Upload

References