{"id":86068,"date":"2025-12-18T07:29:48","date_gmt":"2025-12-18T07:29:48","guid":{"rendered":""},"modified":"-0001-11-30T00:00:00","modified_gmt":"-0001-11-30T06:00:00","slug":"cve-2023-49550-denial-of-service-vulnerability-in-cesanta-mjs-2-20-0","status":"publish","type":"post","link":"https:\/\/www.ameeba.com\/blog\/cve-2023-49550-denial-of-service-vulnerability-in-cesanta-mjs-2-20-0\/","title":{"rendered":"<strong>CVE-2023-49550: Denial of Service Vulnerability in Cesanta mjs 2.20.0<\/strong>"},"content":{"rendered":"<p><strong>Overview<\/strong><\/p>\n<p>A significant cybersecurity vulnerability has been identified in Cesanta mjs 2.20.0, a popular JavaScript engine for embedded systems. This vulnerability, designated as CVE-2023-49550, allows a remote attacker to cause a denial of service, potentially leading to system compromise or data leakage. Given the widespread use of Cesanta mjs in embedded systems, it is critical to understand this vulnerability and implement appropriate mitigation strategies.<\/p>\n<p><strong>Vulnerability Summary<\/strong><\/p>\n<p>CVE ID: CVE-2023-49550<br \/>\nSeverity: High (CVSS: 7.5)<br \/>\nAttack Vector: Network<br \/>\nPrivileges Required: None<br \/>\nUser Interaction: None<br \/>\nImpact: A successful exploit may lead to system compromise or data leakage.<\/p>\n<p><strong>Affected Products<\/strong><\/p><div id=\"ameeb-3185905977\" 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: 720px;\">\r\n  <h2 style=\"margin-top: 0; font-size: 22px; font-weight: 600; display: flex; align-items: center; letter-spacing: -0.02em;\">\r\n    <a href=\"https:\/\/www.ameeba.com\/chat\" style=\"display: inline-flex; align-items: center; margin-right: 10px;\">\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: 42px; height: 42px;\" \/>\r\n    <\/a>\r\n    Share secrets securely\r\n  <\/h2>\r\n\r\n  <p style=\"margin-bottom: 14px; color: #d1d5db;\">\r\n    Ameeba is private infrastructure for communication and sensitive work built on encrypted identity instead of exposed corporate identity systems.\r\n  <\/p>\r\n\r\n  <p style=\"margin-bottom: 18px; color: #a1a1aa;\">\r\n    Passwords, credentials, confidential files, screenshots, internal discussions, sensitive AI context, and private coordination should not become exposed across ordinary communication platforms.\r\n  <\/p>\r\n\r\n  <ul style=\"list-style: none; padding-left: 0; margin-bottom: 24px; color: #e4e4e7;\">\r\n    <li style=\"margin-bottom: 8px;\">\u2022 Encrypted identity<\/li>\r\n    <li style=\"margin-bottom: 8px;\">\u2022 Private Spaces for organizations and teams<\/li>\r\n    <li style=\"margin-bottom: 8px;\">\u2022 End-to-end encrypted chat, calls, files, and notes<\/li>\r\n    <li style=\"margin-bottom: 8px;\">\u2022 Sensitive AI work and protected collaboration<\/li>\r\n    <li>\u2022 Built for information that cannot leak<\/li>\r\n  <\/ul>\r\n\r\n  <p style=\"font-style: italic; font-weight: 600; margin-bottom: 24px; color: #ffffff;\">\r\n    Our mission is to secure human work alongside AI.\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: 8px; font-weight: 500;\">\r\n      Download Ameeba\r\n    <\/a>\r\n\r\n    <a href=\"https:\/\/www.ameeba.com\/chat\" style=\"border: 1px solid #ffffff; color: #ffffff; padding: 10px 20px; text-decoration: none; border-radius: 8px; font-weight: 500;\">\r\n      Learn More\r\n    <\/a>\r\n  <\/div>\r\n<\/div><\/div>\n<p>Product | Affected Versions<\/p>\n<p>Cesanta mjs | 2.20.0<\/p>\n<p><strong>How the Exploit Works<\/strong><\/p>\n<p>The vulnerability resides in the mjs+0x4ec508 component of Cesanta mjs 2.20.0. A remote attacker can exploit this vulnerability by sending specially crafted data to the affected system. Upon successful exploitation, the system enters a denial-of-service state, potentially compromising the system and resulting in data leakage.<\/p>\n<p><strong>Conceptual Example Code<\/strong><\/p><div id=\"ameeb-2168887111\" 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>An example of how this vulnerability might be exploited is presented below. This is a simplified representation and may not represent actual exploit code.<\/p>\n<pre><code class=\"\" data-line=\"\">POST \/mjs+0x4ec508 HTTP\/1.1\nHost: target.example.com\nContent-Type: application\/json\n{ &quot;exploit_data&quot;: &quot;specially crafted data&quot; }<\/code><\/pre>\n<p>In this example, the attacker sends a POST request to the mjs+0x4ec508 endpoint with specially crafted data in the payload. If the exploit is successful, the system would enter a denial-of-service state.<\/p>\n<p><strong>Mitigation Guidance<\/strong><\/p>\n<p>Users of Cesanta mjs 2.20.0 should apply the vendor-supplied patch to rectify this vulnerability as soon as possible. As a temporary mitigation measure, users may also consider deploying a Web Application Firewall (WAF) or Intrusion Detection System (IDS) to detect and prevent potential exploit attempts.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Overview A significant cybersecurity vulnerability has been identified in Cesanta mjs 2.20.0, a popular JavaScript engine for embedded systems. This vulnerability, designated as CVE-2023-49550, allows a remote attacker to cause a denial of service, potentially leading to system compromise or data leakage. Given the widespread use of Cesanta mjs in embedded systems, it is critical [&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-86068","post","type-post","status-publish","format-standard","hentry"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/86068","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=86068"}],"version-history":[{"count":0,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/86068\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/media?parent=86068"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/categories?post=86068"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/tags?post=86068"},{"taxonomy":"vendor","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/vendor?post=86068"},{"taxonomy":"product","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/product?post=86068"},{"taxonomy":"attack_vector","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/attack_vector?post=86068"},{"taxonomy":"asset_type","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/asset_type?post=86068"},{"taxonomy":"severity","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/severity?post=86068"},{"taxonomy":"exploit_status","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/exploit_status?post=86068"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}