CVE-2021-39356: 
WordPress vulnerability analysis and mitigation

The Content Staging WordPress plugin (versions up to and including 2.0.1) was identified with a Stored Cross-Site Scripting vulnerability (CVE-2021-39356), discovered and reported by the Thinkland Security Team. The vulnerability affects multi-site installations where unfilteredhtml is disabled for administrators, and sites where unfilteredhtml is disabled (NVD).

The vulnerability stems from insufficient input validation and escaping via several parameters that are echoed out via the ~/templates/settings.php file. This security flaw allows attackers with administrative user access to inject arbitrary web scripts. The vulnerability has been assigned a CVSS v3.1 base score of 4.8 (Medium) by NIST with vector string CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N, while Wordfence assessed it at 5.5 (Medium) with vector string CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:L/A:N (NVD).

The vulnerability allows attackers with administrative access to inject malicious web scripts into the application, potentially affecting other users who access the compromised pages. This could lead to client-side attacks and potential data exposure in the context of the affected WordPress installation (NVD).

Users should upgrade to a version newer than 2.0.1 of the Content Staging plugin to address this vulnerability. For installations where immediate updating is not possible, limiting administrative access and ensuring proper security controls around user permissions is recommended (NVD).