Zero-day vulnerability in Easy WP SMTP

Deserialization of Untrusted Data

WordPress websites were under attack due to vulnerability in a popular WP plugin since March 15, 2019.

Vulnerability details

Advisory: SB2019031702 - Insecure deserialization in Easy WP SMTP plugin for WordPress

Vulnerable component: Easy WP SMTP

CVE-ID:

CVSSv3 score: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:H/RL:O/RC:C

CWE-ID: CWE-502 - Deserialization of Untrusted Data

Description:

The vulnerability allows a remote attacker to compromise vulnerable website.

The vulnerability exists due to insecure input validation when processing serialized data passed via the "swpsmtp_import_settings" HTTP POST parameter to /easy-wp-smtp.php script. A remote unauthenticated attacker can import arbitrary wp_options and reconfigure WordPress to allow user registration with administrative privileges.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable website.

Note: this vulnerability is being actively exploited in the wild.

External links:

https://blog.nintechnet.com/critical-0day-vulnerability-fixed-in-wordpress-easy-wp-smtp-plugin/

About zero-day vulnerabilities

Zero-day vulnerability is an undisclosed vulnerability in software that hackers can exploit to compromise computer programs, gain unauthorized access to sensitive data, penetrate networks, etc. We consider vulnerability a zero-day when there is no solution provided from software vendor and the vulnerability is being actively exploited by malicious actors.

Zero-day candidate is a potential zero-day vulnerability in software which might have been used in targeted attacks, however there is no evidence to support this suggestion.