{"id":1301,"date":"2025-10-18T20:30:03","date_gmt":"2025-10-18T18:30:03","guid":{"rendered":"https:\/\/blog.chrisse.se\/?p=1301"},"modified":"2025-10-18T20:30:03","modified_gmt":"2025-10-18T18:30:03","slug":"when-your-enterprise-pki-becomes-one-of-your-enemies-part-8","status":"publish","type":"post","link":"https:\/\/blog.chrisse.se\/?p=1301","title":{"rendered":"When your Enterprise PKI becomes one of your enemies (Part 8)"},"content":{"rendered":"\n<p>So the security updates for October has arrived and \u201cAllowNtAuthPolicyBypass\u201d registry key is now gone from kdcsvc.dll &#8211; All CAs that issue certificates to be used for PKINIT against Active Directory must now be trusted in NTAuth.<br><br>Please do not add CA&#8217;s to NTAuth that you don&#8217;t trust, as any one who can issue a certificate with subject of choice from those still can impersonate any user account within your forest e.g. a DA\/EA and this is regardless of StrongCertificateBindingEnforcement and NTAuthEnforcement.<br><br>A good solution to keep NTAuth safe is NTAuthGuard by Carl S\u00f6rqvist.<br><\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"389\" src=\"https:\/\/blog.chrisse.se\/wp-content\/uploads\/2025\/10\/image-4-1024x389.png\" alt=\"\" class=\"wp-image-1302\" srcset=\"https:\/\/blog.chrisse.se\/wp-content\/uploads\/2025\/10\/image-4-1024x389.png 1024w, https:\/\/blog.chrisse.se\/wp-content\/uploads\/2025\/10\/image-4-300x114.png 300w, https:\/\/blog.chrisse.se\/wp-content\/uploads\/2025\/10\/image-4-768x292.png 768w, https:\/\/blog.chrisse.se\/wp-content\/uploads\/2025\/10\/image-4.png 1147w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/figure>\n\n\n\n<p><br>Read more about the NTAuthGuard solution \u2013 how to set it up and get all the required content from Carl\u2019s GitHub <a href=\"https:\/\/github.com\/CarlSorqvist\/PsCertTools\/tree\/main\/NTAuthGuard\">https:\/\/github.com\/CarlSorqvist\/PsCertTools\/tree\/main\/NTAuthGuard<\/a><\/p>\n\n\n\n<p>But as I use to say, there is always a secret key &#8211; as with &#8220;StrongCertificateBindingEnforcement&#8221; another key instead of &#8220;AllowNtAuthPolicyBypass&#8221; can be used to &#8220;unsupported so far I know&#8221; turn off the NTAuthEnforcement requirement. You will find it by using:<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>.\\strings.exe -n 5 -o -f 671232 C:\\Windows\\system32\\kdcsvc.dll<\/code><\/pre>\n\n\n\n<p>But do not use it, you will be subject to vulnerabilities, however this new regkey has two modes:<\/p>\n\n\n\n<ol class=\"wp-block-list indent40\">\n<li>if set to &#8220;0&#8221; it will just silently ignore if the CA is in NTAuth or not<\/li>\n\n\n\n<li>if set to &#8220;1&#8221;  it will log Event 45 for KDC<\/li>\n<\/ol>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"319\" src=\"https:\/\/blog.chrisse.se\/wp-content\/uploads\/2025\/10\/image-5-1024x319.png\" alt=\"\" class=\"wp-image-1303\" srcset=\"https:\/\/blog.chrisse.se\/wp-content\/uploads\/2025\/10\/image-5-1024x319.png 1024w, https:\/\/blog.chrisse.se\/wp-content\/uploads\/2025\/10\/image-5-300x93.png 300w, https:\/\/blog.chrisse.se\/wp-content\/uploads\/2025\/10\/image-5-768x239.png 768w, https:\/\/blog.chrisse.se\/wp-content\/uploads\/2025\/10\/image-5.png 1069w\" sizes=\"auto, (max-width: 767px) 89vw, (max-width: 1000px) 54vw, (max-width: 1071px) 543px, 580px\" \/><\/figure>\n\n\n\n<p><\/p>\n\n\n\n<p>By the way my session at HIPConf25 on this subject is now available online for everyone to watch:<br><a href=\"https:\/\/www.hipconf.com\/resources\/enterprise-pki-today-friend-or-foe\/\">Enterprise PKI Today: Friend or Foe? &#8211; Hip Conf<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>So the security updates for October has arrived and \u201cAllowNtAuthPolicyBypass\u201d registry key is now gone from kdcsvc.dll &#8211; All CAs that issue certificates to be used for PKINIT against Active Directory must now be trusted in NTAuth. Please do not add CA&#8217;s to NTAuth that you don&#8217;t trust, as any one who can issue a &hellip; <\/p>\n<p class=\"link-more\"><a href=\"https:\/\/blog.chrisse.se\/?p=1301\" class=\"more-link\">Continue reading<span class=\"screen-reader-text\"> &#8220;When your Enterprise PKI becomes one of your enemies (Part 8)&#8221;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_exactmetrics_skip_tracking":false,"_exactmetrics_sitenote_active":false,"_exactmetrics_sitenote_note":"","_exactmetrics_sitenote_category":0,"footnotes":""},"categories":[36,1],"tags":[30],"class_list":["post-1301","post","type-post","status-publish","format-standard","hentry","category-public-key-infrastructure-pki","category-uncategorized","tag-pki"],"_links":{"self":[{"href":"https:\/\/blog.chrisse.se\/index.php?rest_route=\/wp\/v2\/posts\/1301","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.chrisse.se\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.chrisse.se\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.chrisse.se\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.chrisse.se\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1301"}],"version-history":[{"count":3,"href":"https:\/\/blog.chrisse.se\/index.php?rest_route=\/wp\/v2\/posts\/1301\/revisions"}],"predecessor-version":[{"id":1306,"href":"https:\/\/blog.chrisse.se\/index.php?rest_route=\/wp\/v2\/posts\/1301\/revisions\/1306"}],"wp:attachment":[{"href":"https:\/\/blog.chrisse.se\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1301"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.chrisse.se\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1301"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.chrisse.se\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1301"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}