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WordPress File Deletion Vulnerability

A vulnerability in the WordPress content management system (CMS) core allows remote unauthenticated users to delete files. An attacker could exploit this gain remote code execution capability on an affected device.
Threat ID:
CC-2515
Category:
Exploit
Threat Severity:
Low
Threat Vector:
Published:
27 June 2018 12:00 AM
Report a cyber attack: call 0300 303 5222 or email [email protected]

This content has been archived

This article no longer conforms to NHS Digital's standards for cyber alerts, and may contain outdated or inaccurate information. Use of this information contained in this page is at your own risk

Summary

A vulnerability in the WordPress content management system (CMS) core allows remote unauthenticated users to delete files. An attacker could exploit this gain remote code execution capability on an affected device.

Affected platforms

The following platforms are known to be affected:

WordPress Core

  • WordPress Core - All versions up to 4.9.6

Threat details

Any user who has access to the post editor (Author level access or greater) on a WordPress site, and can upload or delete images, is able to insert code to delete CMS core security files. An attacker can target specific files that, when deleted, will allow them to reinstall their own databases on the affected site. This would give the attacker full control of the compromised site.

The following files can be deleted:

  • .htaccess Typically this file does not pose a security risk if deleted but in some circumstances can store security-related permission constraints.
  • index.php files Deleting these files provides a full list of directories that contain them.
  • wp-config.php Deletion of this file triggers the re-installation process by which an attacker can inject their own database file.

Remediation steps

Type Step

At the time of publication WordPress are aware of the vulnerability and are in the process of producing an update to mitigate this vulnerability. Users are advised to apply this update to their affected systems as soon as it becomes available.

A temporary hotfix has been produced by the researchers who disclosed the vulnerability that prevents security files from being deleted can be found here. Users are advised that this fix has not been tested and they should be applied at their own risk.

Last edited: 17 February 2020 12:57 pm