{"id":85932,"date":"2025-12-01T06:40:35","date_gmt":"2025-12-01T06:40:35","guid":{"rendered":""},"modified":"-0001-11-30T00:00:00","modified_gmt":"-0001-11-30T06:00:00","slug":"cve-2024-21637-reflected-cross-site-scripting-vulnerability-in-authentik-openid-connect-flows","status":"publish","type":"post","link":"https:\/\/www.ameeba.com\/blog\/cve-2024-21637-reflected-cross-site-scripting-vulnerability-in-authentik-openid-connect-flows\/","title":{"rendered":"<strong>CVE-2024-21637: Reflected Cross-Site Scripting Vulnerability in Authentik OpenID Connect Flows<\/strong>"},"content":{"rendered":"<p><strong>Overview<\/strong><\/p>\n<p>The cybersecurity vulnerability CVE-2024-21637 is a serious threat that pertains to Authentik, an open-source Identity Provider. The vulnerability involves a reflected Cross-Site Scripting (XSS) attack in OpenID Connect flows, which potentially allows an attacker to escalate privileges and compromise the system. Given the widespread adoption of Authentik as an Identity Provider, this vulnerability should not be overlooked and needs immediate attention.<\/p>\n<p><strong>Vulnerability Summary<\/strong><\/p>\n<p>CVE ID: CVE-2024-21637<br \/>\nSeverity: High (7.6 CVSS Score)<br \/>\nAttack Vector: Network<br \/>\nPrivileges Required: Low<br \/>\nUser Interaction: Required<br \/>\nImpact: Potential system compromise or data leakage<\/p>\n<p><strong>Affected Products<\/strong><\/p><div id=\"ameeb-3535618160\" class=\"ameeb-content-2 ameeb-entity-placement\"><div style=\"border-left: 4px solid #555; padding-left: 20px; margin: 48px 0; font-family: Roboto, sans-serif; color: #ffffff; line-height: 1.6; max-width: 700px;\">\r\n  <h2 style=\"margin-top: 0; font-size: 20px; font-weight: 600; display: flex; align-items: center;\">\r\n    <a href=\"https:\/\/www.ameeba.com\/chat\" style=\"display: inline-flex; align-items: center; margin-right: 8px;\">\r\n      <img decoding=\"async\" src=\"https:\/\/www.ameeba.com\/blog\/wp-content\/uploads\/2025\/10\/Best-App-icon-Ameeba.png\" alt=\"Ameeba Chat Icon\" style=\"width: 40px; height: 40px;\" \/>\r\n    <\/a>\r\n    A new way to communicate\r\n  <\/h2>\r\n\r\n  <p style=\"margin-bottom: 12px;\">\r\n    Ameeba Chat is built on encrypted identity, not personal profiles.\r\n  <\/p>\r\n\r\n  <p style=\"margin-bottom: 16px;\">\r\n    Message, call, share files, and coordinate with identities kept separate.\r\n  <\/p>\r\n\r\n  <ul style=\"list-style: none; padding-left: 0; margin-bottom: 20px;\">\r\n    <li>\u2022 Encrypted identity<\/li>\r\n    <li>\u2022 Ameeba Chat authenticates access<\/li>\r\n    <li>\u2022 Aliases and categories<\/li>\r\n    <li>\u2022 End-to-end encrypted chat, calls, and files<\/li>\r\n    <li>\u2022 Secure notes for sensitive information<\/li>\r\n  <\/ul>\r\n\r\n  <p style=\"font-style: italic; font-weight: 600; margin-bottom: 24px;\">\r\n    Private communication, rethought.\r\n  <\/p>\r\n\r\n  <div style=\"display: flex; flex-wrap: wrap; gap: 12px;\">\r\n    <a href=\"https:\/\/www.ameeba.com\/chat\/download\" style=\"background-color: #ffffff; color: #000000; padding: 10px 20px; text-decoration: none; border-radius: 6px; font-weight: 500;\">Download Ameeba Chat<\/a>\r\n    <a href=\"https:\/\/www.ameeba.com\/chat\" style=\"border: 1px solid #ffffff; color: #ffffff; padding: 10px 20px; text-decoration: none; border-radius: 6px; font-weight: 500;\">Learn More<\/a>\r\n  <\/div>\r\n<\/div>\r\n<\/div>\n<p>Product | Affected Versions<\/p>\n<p>Authentik | Prior to 2023.10.6<br \/>\nAuthentik | Prior to 2023.8.6<\/p>\n<p><strong>How the Exploit Works<\/strong><\/p>\n<p>This vulnerability exploits a flaw in Authentik&#8217;s handling of JavaScript-URIs in OpenID Connect flows with `response_mode=form_post`. In essence, a user can inject malicious JavaScript code that is then reflected back to the user&#8217;s browser by the server. This code could be designed to steal sensitive user data or perform actions on behalf of the user, leading to privilege escalation and potential system compromise.<\/p>\n<p><strong>Conceptual Example Code<\/strong><\/p><div id=\"ameeb-1298271677\" class=\"ameeb-content ameeb-entity-placement\"><div class=\"poptin-embedded\" data-id=\"f6b387694f681\"><\/div>\r\n\r\n\r\n\r\n\r\n\r\n<\/div>\n<p>Below is a conceptual example of how the vulnerability might be exploited:<\/p>\n<pre><code class=\"\" data-line=\"\">POST \/oidc\/authorize HTTP\/1.1\nHost: target.example.com\nContent-Type: application\/x-www-form-urlencoded\nresponse_type=code&amp;client_id=client&amp;state=1234&amp;redirect_uri=javascript:malicious_code_here<\/code><\/pre>\n<p>In this example, the `redirect_uri` parameter is injected with malicious JavaScript code, which is then reflected back to the user&#8217;s browser by the server, leading to potential compromise.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Overview The cybersecurity vulnerability CVE-2024-21637 is a serious threat that pertains to Authentik, an open-source Identity Provider. The vulnerability involves a reflected Cross-Site Scripting (XSS) attack in OpenID Connect flows, which potentially allows an attacker to escalate privileges and compromise the system. Given the widespread adoption of Authentik as an Identity Provider, this vulnerability should [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"om_disable_all_campaigns":false,"footnotes":""},"categories":[],"tags":[],"vendor":[],"product":[],"attack_vector":[],"asset_type":[],"severity":[],"exploit_status":[],"class_list":["post-85932","post","type-post","status-publish","format-standard","hentry"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/85932","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/comments?post=85932"}],"version-history":[{"count":0,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/85932\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/media?parent=85932"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/categories?post=85932"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/tags?post=85932"},{"taxonomy":"vendor","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/vendor?post=85932"},{"taxonomy":"product","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/product?post=85932"},{"taxonomy":"attack_vector","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/attack_vector?post=85932"},{"taxonomy":"asset_type","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/asset_type?post=85932"},{"taxonomy":"severity","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/severity?post=85932"},{"taxonomy":"exploit_status","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/exploit_status?post=85932"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}