{"id":86682,"date":"2026-03-14T03:15:57","date_gmt":"2026-03-14T03:15:57","guid":{"rendered":""},"modified":"-0001-11-30T00:00:00","modified_gmt":"-0001-11-30T06:00:00","slug":"cve-2025-53537-severe-memory-leak-vulnerability-in-libhtp","status":"publish","type":"post","link":"https:\/\/www.ameeba.com\/blog\/cve-2025-53537-severe-memory-leak-vulnerability-in-libhtp\/","title":{"rendered":"<strong>CVE-2025-53537: Severe Memory Leak Vulnerability in LibHTP<\/strong>"},"content":{"rendered":"<p><strong>Overview<\/strong><\/p>\n<p>This report details a significant vulnerability in LibHTP, a security-aware parser for the HTTP protocol. The vulnerability, referenced as CVE-2025-53537, affects versions 0.5.50 and below, allowing attackers to starve a process of memory, causing loss of visibility. This particular vulnerability carries significant implications for any entity using an affected LibHTP version, potentially leading to system compromise or data leakage.<\/p>\n<p><strong>Vulnerability Summary<\/strong><\/p>\n<p>CVE ID: CVE-2025-53537<br \/>\nSeverity: High (7.5)<br \/>\nAttack Vector: Network<br \/>\nPrivileges Required: None<br \/>\nUser Interaction: None<br \/>\nImpact: Potential system compromise or data leakage<\/p>\n<p><strong>Affected Products<\/strong><\/p><div id=\"ameeb-3371982358\" 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>LibHTP | 0.5.50 and below<\/p>\n<p><strong>How the Exploit Works<\/strong><\/p>\n<p>The CVE-2025-53537 vulnerability originates from a memory leak in LibHTP&#8217;s handling of HTTP traffic. If an attacker can generate sufficient traffic, it can starve the process of memory. This memory starvation can lead to a loss of visibility, which can potentially pave the way for further attacks and exploitation.<\/p>\n<p><strong>Conceptual Example Code<\/strong><\/p><div id=\"ameeb-3431484451\" 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>Though the specifics of the exploit are not public, an attacker might generate massive traffic to the target server to induce memory leak. A conceptual example of how this might be done is shown below:<\/p>\n<pre><code class=\"\" data-line=\"\">POST \/ HTTP\/1.1\nHost: target.example.com\nContent-Type: application\/x-www-form-urlencoded\ndata=AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA...<\/code><\/pre>\n<p>This example sends a POST request with a large payload to the target server. An attacker might automate this and send multiple requests concurrently, potentially leading to memory exhaustion.<\/p>\n<p><strong>Mitigation and Solution<\/strong><\/p>\n<p>The LibHTP team has released a fix for this vulnerability in version 0.5.51. It is highly recommended that users update to this version to avoid exposure. If unable to update immediately, users can mitigate the risk by setting `suricata.yaml app-layer.protocols.http.libhtp.default-config.lzma-enabled` to false. Alternatively, using a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can provide a temporary mitigation against potential exploits.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Overview This report details a significant vulnerability in LibHTP, a security-aware parser for the HTTP protocol. The vulnerability, referenced as CVE-2025-53537, affects versions 0.5.50 and below, allowing attackers to starve a process of memory, causing loss of visibility. This particular vulnerability carries significant implications for any entity using an affected LibHTP version, potentially leading to [&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-86682","post","type-post","status-publish","format-standard","hentry"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/86682","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=86682"}],"version-history":[{"count":0,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/86682\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/media?parent=86682"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/categories?post=86682"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/tags?post=86682"},{"taxonomy":"vendor","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/vendor?post=86682"},{"taxonomy":"product","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/product?post=86682"},{"taxonomy":"attack_vector","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/attack_vector?post=86682"},{"taxonomy":"asset_type","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/asset_type?post=86682"},{"taxonomy":"severity","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/severity?post=86682"},{"taxonomy":"exploit_status","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/exploit_status?post=86682"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}