Description
WordPress is prone to a cross-domain Flash injection vulnerability. An attacker may leverage this issue to execute arbitrary script code in the browser of an unsuspecting user in the context of the affected site, allowing the attacker to steal cookie-based authentication credentials, or to fool a user into inserting credentials on a fake Flash form. WordPress versions 4.1.x ranging from 4.1 and up to (and including) 4.1.21 are vulnerable.
Remediation
Update to WordPress version 4.1.22 or latest
References
https://opnsec.com/2017/10/cve-2016-9263-unpatched-xsf-vulnerability-in-wordpress/
https://opnsec.com/2017/10/flashme-wordpress-vulnerability-disclosure-cve-2016-9263/
Related Vulnerabilities
Moodle Permissions, Privileges, and Access Controls Vulnerability (CVE-2012-6106)
WordPress Plugin Product Reviews Import Export for WooCommerce CSV Injection (1.4.8)
Atlassian Jira Cross-Site Request Forgery (CSRF) Vulnerability (CVE-2017-18033)
WordPress Plugin WordPress Payments-GetPaid Cross-Site Scripting (2.3.3)
WordPress Plugin WP Canvas-Shortcodes Cross-Site Scripting (2.06)