CVE-2020-35135: 
WordPress vulnerability analysis and mitigation

The ultimate-category-excluder plugin before version 1.2 for WordPress contains a Cross-Site Request Forgery (CSRF) vulnerability in the ultimate-category-excluder.php file. The vulnerability was discovered and disclosed on December 11, 2020, affecting all versions of the plugin prior to 1.2. The plugin, which allows users to exclude categories from front pages, feeds, archives, and search results, failed to implement proper CSRF protection in its options page (NVD, WPScan).

The vulnerability stems from the plugin's failure to check for CSRF nonce in its options page, making it susceptible to cross-site request forgery attacks. The vulnerability has been assigned a CVSS v3.1 base score of 8.8 (HIGH) with the vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H. The issue is classified under CWE-352 (Cross-Site Request Forgery) (NVD).

The vulnerability allows attackers to perform CSRF attacks against logged-in users, potentially leading to unauthorized modifications of category exclusion settings. This could result in unauthorized changes to the website's content visibility settings, affecting the display of categories on the front page, feeds, archives, and search results (WPScan).

The vulnerability requires user interaction to be exploited, as indicated by the CVSS metrics. An attacker would need to trick an authenticated administrator into performing specific actions while logged into the WordPress dashboard (NVD).

The vulnerability was patched in version 1.2 of the Ultimate Category Excluder plugin. The fix includes the implementation of proper CSRF protection through the addition of nonce verification. Users are advised to upgrade to version 1.2 or later, and review their UCE category settings to ensure they are set as expected (WordPress Plugin).