{"id":86900,"date":"2026-04-08T16:22:19","date_gmt":"2026-04-08T16:22:19","guid":{"rendered":""},"modified":"-0001-11-30T00:00:00","modified_gmt":"-0001-11-30T06:00:00","slug":"cve-2025-55763-buffer-overflow-vulnerability-in-civetweb-s-uri-parser","status":"publish","type":"post","link":"https:\/\/www.ameeba.com\/blog\/cve-2025-55763-buffer-overflow-vulnerability-in-civetweb-s-uri-parser\/","title":{"rendered":"<strong>CVE-2025-55763: Buffer Overflow Vulnerability in CivetWeb&#8217;s URI Parser<\/strong>"},"content":{"rendered":"<p><strong>Overview<\/strong><\/p>\n<p>CVE-2025-55763 describes a critical buffer overflow vulnerability present in the URI parser of CivetWeb versions 1.14 through 1.16. This vulnerability can be exploited by a remote attacker to execute arbitrary code on the target system or cause a denial of service via a specially crafted HTTP request. It affects all systems running affected versions of CivetWeb, and due to its potential for system compromise and data leakage, it warrants immediate attention.<\/p>\n<p><strong>Vulnerability Summary<\/strong><\/p>\n<p>CVE ID: CVE-2025-55763<br \/>\nSeverity: High (CVSS 7.5)<br \/>\nAttack Vector: Network<br \/>\nPrivileges Required: None<br \/>\nUser Interaction: None<br \/>\nImpact: May lead to system compromise, denial of service, or data leakage on successful exploitation<\/p>\n<p><strong>Affected Products<\/strong><\/p><div id=\"ameeb-1088135990\" 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>CivetWeb | 1.14 to 1.16 (inclusive)<\/p>\n<p><strong>How the Exploit Works<\/strong><\/p>\n<p>The vulnerability exists due to insufficient handling of input during the processing of HTTP requests by CivetWeb&#8217;s URI parser. A remote attacker can send a specially crafted HTTP request with an unusually long URI, causing a buffer overflow condition. This can corrupt heap memory, resulting in the execution of arbitrary code under the context of the application or cause the application to crash, leading to a denial of service.<\/p>\n<p><strong>Conceptual Example Code<\/strong><\/p><div id=\"ameeb-3703463471\" 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>A possible exploitation of the vulnerability might involve a POST request with a long URI, as shown in the conceptual example below:<\/p>\n<pre><code class=\"\" data-line=\"\">POST \/AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA... HTTP\/1.1\nHost: target.example.com\nContent-Type: application\/json\n{ &quot;malicious_payload&quot;: &quot;...&quot; }<\/code><\/pre>\n<p>Here, the long string of &#8216;A&#8217;s represents an unusually long URI used to trigger the buffer overflow.<\/p>\n<p><strong>Mitigation<\/strong><\/p>\n<p>End users are recommended to apply the latest vendor-supplied patches as soon as they are available. If a patch is not immediately available, using a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can offer temporary mitigation by detecting and blocking crafted HTTP requests that attempt to exploit this vulnerability.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Overview CVE-2025-55763 describes a critical buffer overflow vulnerability present in the URI parser of CivetWeb versions 1.14 through 1.16. This vulnerability can be exploited by a remote attacker to execute arbitrary code on the target system or cause a denial of service via a specially crafted HTTP request. It affects all systems running affected versions [&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-86900","post","type-post","status-publish","format-standard","hentry"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/86900","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=86900"}],"version-history":[{"count":0,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/86900\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/media?parent=86900"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/categories?post=86900"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/tags?post=86900"},{"taxonomy":"vendor","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/vendor?post=86900"},{"taxonomy":"product","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/product?post=86900"},{"taxonomy":"attack_vector","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/attack_vector?post=86900"},{"taxonomy":"asset_type","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/asset_type?post=86900"},{"taxonomy":"severity","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/severity?post=86900"},{"taxonomy":"exploit_status","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/exploit_status?post=86900"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}