{"id":86238,"date":"2026-01-08T23:20:24","date_gmt":"2026-01-08T23:20:24","guid":{"rendered":""},"modified":"-0001-11-30T00:00:00","modified_gmt":"-0001-11-30T06:00:00","slug":"cve-2025-3857-critical-denial-of-service-vulnerability-in-amazon-iondotnet","status":"publish","type":"post","link":"https:\/\/www.ameeba.com\/blog\/cve-2025-3857-critical-denial-of-service-vulnerability-in-amazon-iondotnet\/","title":{"rendered":"<strong>CVE-2025-3857: Critical Denial of Service Vulnerability in Amazon.IonDotnet<\/strong>"},"content":{"rendered":"<p><strong>Overview<\/strong><\/p>\n<p>CVE-2025-3857 is a severe vulnerability in Amazon.IonDotnet&#8217;s RawBinaryReader class that could potentially lead to system compromise or data leakage. This vulnerability affects applications using Amazon.IonDotnet for reading binary Ion data, and it poses a significant risk due to its potential to trigger an infinite loop condition, resulting in a denial of service.<\/p>\n<p><strong>Vulnerability Summary<\/strong><\/p>\n<p>CVE ID: CVE-2025-3857<br \/>\nSeverity: High, CVSS 7.5<br \/>\nAttack Vector: Network<br \/>\nPrivileges Required: None<br \/>\nUser Interaction: None<br \/>\nImpact: System compromise or data leakage<\/p>\n<p><strong>Affected Products<\/strong><\/p><div id=\"ameeb-3410935081\" 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>Amazon.IonDotnet | All versions prior to 1.3.1<\/p>\n<p><strong>How the Exploit Works<\/strong><\/p>\n<p>The exploit for this vulnerability involves sending malformed or truncated Ion data to an application using Amazon.IonDotnet. The lack of checks on the number of bytes read from the underlying stream while deserializing the binary format results in an infinite loop condition. This situation can cause system resources to be exhausted, leading to a denial of service. Additionally, in some cases, this vulnerability could be leveraged to compromise the system or leak data.<\/p>\n<p><strong>Conceptual Example Code<\/strong><\/p><div id=\"ameeb-1351611062\" 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>Here&#8217;s a conceptual example of a malicious payload that could potentially exploit this vulnerability:<\/p>\n<pre><code class=\"\" data-line=\"\">POST \/api\/parse_ion HTTP\/1.1\nHost: target.example.com\nContent-Type: application\/ion\n{\n&quot;malformed_ion_data&quot;: &quot;...&quot;\n}<\/code><\/pre>\n<p>In this example, &#8220;malformed_ion_data&#8221; would contain Ion data that is purposely malformed or truncated to exploit the vulnerability.<\/p>\n<p><strong>Mitigation Guidance<\/strong><\/p>\n<p>Users are advised to upgrade to Amazon.IonDotnet version 1.3.1 to mitigate this vulnerability. If an immediate upgrade is not possible, the use of a Web Application Firewall (WAF) or Intrusion Detection System (IDS) could serve as a temporary mitigation measure. Ensure any forked or derivative code is patched to incorporate the new fixes.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Overview CVE-2025-3857 is a severe vulnerability in Amazon.IonDotnet&#8217;s RawBinaryReader class that could potentially lead to system compromise or data leakage. This vulnerability affects applications using Amazon.IonDotnet for reading binary Ion data, and it poses a significant risk due to its potential to trigger an infinite loop condition, resulting in a denial of service. Vulnerability Summary [&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-86238","post","type-post","status-publish","format-standard","hentry"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/86238","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=86238"}],"version-history":[{"count":0,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/86238\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/media?parent=86238"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/categories?post=86238"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/tags?post=86238"},{"taxonomy":"vendor","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/vendor?post=86238"},{"taxonomy":"product","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/product?post=86238"},{"taxonomy":"attack_vector","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/attack_vector?post=86238"},{"taxonomy":"asset_type","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/asset_type?post=86238"},{"taxonomy":"severity","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/severity?post=86238"},{"taxonomy":"exploit_status","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/exploit_status?post=86238"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}