{"id":85895,"date":"2025-11-26T15:28:49","date_gmt":"2025-11-26T15:28:49","guid":{"rendered":""},"modified":"-0001-11-30T00:00:00","modified_gmt":"-0001-11-30T06:00:00","slug":"cve-2025-47281-denial-of-service-vulnerability-in-kyverno-policy-engine","status":"publish","type":"post","link":"https:\/\/www.ameeba.com\/blog\/cve-2025-47281-denial-of-service-vulnerability-in-kyverno-policy-engine\/","title":{"rendered":"<strong>CVE-2025-47281: Denial of Service Vulnerability in Kyverno Policy Engine<\/strong>"},"content":{"rendered":"<p><strong>Overview<\/strong><\/p>\n<p>A severe vulnerability identified as CVE-2025-47281 has been discovered in the Kyverno policy engine, a tool often utilized by cloud-native platform engineering teams. This flaw, affecting versions 1.14.1 and below, could allow attackers to cause a Denial of Service (DoS), potentially leading to system compromise or data leakage.<\/p>\n<p><strong>Vulnerability Summary<\/strong><\/p>\n<p>CVE ID: CVE-2025-47281<br \/>\nSeverity: High (7.7 CVSS)<br \/>\nAttack Vector: Network<br \/>\nPrivileges Required: Low<br \/>\nUser Interaction: None<br \/>\nImpact: Denial of Service, potential system compromise, and data leakage<\/p>\n<p><strong>Affected Products<\/strong><\/p><div id=\"ameeb-1388509430\" 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>Kyverno Policy Engine | 1.14.1 and below<\/p>\n<p><strong>How the Exploit Works<\/strong><\/p>\n<p>The vulnerability arises due to the improper handling of JMESPath variable substitutions in Kyverno. Attackers with permissions to create or update Kyverno policies can craft expressions using the {{@}} variable combined with a pipe and an invalid JMESPath function. This leads to a nil value being substituted into the policy structure. Subsequent processing by internal functions, specifically getValueAsStringMap, which expect string values, result in a panic due to a type assertion failure. This crashes Kyverno worker threads in the admission controller and causes continuous crashes of the reports controller pod.<\/p>\n<p><strong>Conceptual Example Code<\/strong><\/p><div id=\"ameeb-1072078228\" 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>Consider the following example of a malicious policy:<\/p>\n<pre><code class=\"\" data-line=\"\">apiVersion: kyverno.io\/v1\nkind: ClusterPolicy\nmetadata:\nname: exploit-cve-2025-47281\nspec:\nrules:\n- name: exploit\nmatch:\nresources:\nkinds:\n- Pod\nmutate:\noverlay:\nspec:\ncontainers:\n- (name): &quot;*&quot;\nresources:\nlimits:\ncpu: &quot;{{@ | non_existent_function }}&quot;<\/code><\/pre>\n<p>In this example, the attacker crafts a malicious expression (`{{@ | non_existent_function }}`) that leads to a nil value being substituted into the policy structure, triggering the vulnerability.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Overview A severe vulnerability identified as CVE-2025-47281 has been discovered in the Kyverno policy engine, a tool often utilized by cloud-native platform engineering teams. This flaw, affecting versions 1.14.1 and below, could allow attackers to cause a Denial of Service (DoS), potentially leading to system compromise or data leakage. Vulnerability Summary CVE ID: CVE-2025-47281 Severity: [&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-85895","post","type-post","status-publish","format-standard","hentry"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/85895","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=85895"}],"version-history":[{"count":0,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/85895\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/media?parent=85895"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/categories?post=85895"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/tags?post=85895"},{"taxonomy":"vendor","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/vendor?post=85895"},{"taxonomy":"product","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/product?post=85895"},{"taxonomy":"attack_vector","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/attack_vector?post=85895"},{"taxonomy":"asset_type","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/asset_type?post=85895"},{"taxonomy":"severity","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/severity?post=85895"},{"taxonomy":"exploit_status","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/exploit_status?post=85895"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}