Several plugins for WordPress by Inisev are vulnerable to unauthorized installation of plugins due to a missing capability check on the handle_installation function that is called via the inisev_installation AJAX aciton in various versions. This makes it possible for authenticated attackers with minimal permissions, such as subscribers, to install select plugins from Inisev on vulnerable sites. CVE-2023-38514 appears to be a duplicate of this vulnerability.
https://plugins.trac.wordpress.org/browser/ultimate-posts-widget/tags/2.2.5/banner/misc.php#L351
https://plugins.trac.wordpress.org/browser/ultimate-posts-widget/tags/2.2.4/banner/misc.php#L343
https://plugins.trac.wordpress.org/browser/pop-up-pop-up/tags/1.2.0/modules/banner/misc.php#L432
https://plugins.trac.wordpress.org/browser/pop-up-pop-up/tags/1.1.9/modules/banner/misc.php#L427
https://plugins.trac.wordpress.org/browser/http-https-remover/tags/3.2.3/banner/misc.php#L427
https://plugins.trac.wordpress.org/browser/enhanced-text-widget/tags/1.5.7/banner/misc.php#L351
https://plugins.trac.wordpress.org/browser/enhanced-text-widget/tags/1.5.6/banner/misc.php#L339
https://plugins.trac.wordpress.org/browser/copy-delete-posts/tags/1.4.0/banner/misc.php#L434
https://plugins.trac.wordpress.org/browser/copy-delete-posts/tags/1.3.8/banner/misc.php#L426
https://plugins.trac.wordpress.org/browser/backup-backup/tags/1.2.8/includes/banner/misc.php#L434
https://plugins.trac.wordpress.org/browser/backup-backup/tags/1.2.7/includes/banner/misc.php#L427