{"id":34701,"date":"2025-05-05T17:15:07","date_gmt":"2025-05-05T17:15:07","guid":{"rendered":""},"modified":"2025-10-01T18:52:02","modified_gmt":"2025-10-02T00:52:02","slug":"cve-2023-35956-heap-based-buffer-overflow-vulnerability-in-gtkwave","status":"publish","type":"post","link":"https:\/\/www.ameeba.com\/blog\/cve-2023-35956-heap-based-buffer-overflow-vulnerability-in-gtkwave\/","title":{"rendered":"<strong>CVE-2023-35956: Heap-Based Buffer Overflow Vulnerability in GTKWave<\/strong>"},"content":{"rendered":"<p><strong>Overview<\/strong><\/p>\n<p>Security vulnerabilities are a significant concern for software developers and users alike. In this post, we&#8217;ll discuss a particular vulnerability identified as CVE-2023-35956 that impacts the GTKWave software, version 3.3.115. This vulnerability is of serious concern due to its potential to enable arbitrary code execution, <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-32857-sql-injection-vulnerability-in-telecontrol-server-basic-leading-to-potential-system-compromise\/\"  data-wpil-monitor-id=\"39751\">leading to potential system<\/a> compromise or data leakage.<br \/>\nGTKWave is a fully <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-58819-unrestricted-file-upload-vulnerability-in-creedally-bulk-featured-image\/\"  data-wpil-monitor-id=\"87003\">featured GTK+ based wave viewer used for viewing VCD files<\/a> (Value Change Dump). It is widely employed in systems where waveform viewing is necessary, especially in digital design environments. Therefore, this <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-22636-cross-site-scripting-vulnerability-in-vr-frases-leads-to-potential-system-compromise\/\"  data-wpil-monitor-id=\"40176\">vulnerability could potentially<\/a> affect a wide range of users, and addressing it is of utmost importance.<\/p>\n<p><strong>Vulnerability Summary<\/strong><\/p>\n<p>CVE ID: CVE-2023-35956<br \/>\nSeverity: High (7.8 CVSS Score)<br \/>\nAttack Vector: Local<br \/>\nPrivileges Required: User<br \/>\nUser Interaction: Required<br \/>\nImpact: <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-3928-unspecified-vulnerability-in-commvault-web-server-leading-to-potential-system-compromise\/\"  data-wpil-monitor-id=\"40374\">Potential system<\/a> compromise or data leakage<\/p>\n<p><strong>Affected Products<\/strong><\/p><div id=\"ameeb-167209958\" 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>GTKWave | 3.3.115<\/p>\n<p><strong>How the Exploit Works<\/strong><\/p>\n<p>The vulnerability in question stems from multiple heap-based <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-28024-buffer-overflow-vulnerability-in-totolink-a810r-v4-1-2cu-5182-b20201026\/\"  data-wpil-monitor-id=\"39563\">buffer overflow<\/a> vulnerabilities in the fstReaderIterBlocks2 VCDATA parsing functionality of GTKWave. Buffer overflow <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-23176-sql-injection-vulnerability-poses-serious-threat-to-data-security\/\"  data-wpil-monitor-id=\"39937\">vulnerabilities typically occur when data<\/a> is written into a buffer and surpasses the buffer&#8217;s boundary, consequently overwriting adjacent memory locations.<br \/>\nIn this case, a specially-crafted .fst <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2023-43958-arbitrary-file-upload-vulnerability-in-hospital-management-system-v4-0\/\"  data-wpil-monitor-id=\"39693\">file can lead to arbitrary<\/a> code execution. A victim would need to open this maliciously crafted file, <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-52478-stored-cross-site-scripting-vulnerability-in-n8n-s-form-trigger-node\/\"  data-wpil-monitor-id=\"79447\">triggering the vulnerability<\/a>. The <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2023-35960-os-command-injection-vulnerabilities-in-gtkwave-s-decompression-functionality\/\"  data-wpil-monitor-id=\"41728\">decompression function `fastlz_decompress` is the primary concern in this vulnerability<\/a>.<\/p>\n<p><strong>Conceptual Example Code<\/strong><\/p><div id=\"ameeb-3894132442\" 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 is a conceptual representation of how an <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-47154-exploitation-of-use-after-free-vulnerability-in-libjs-in-ladybird\/\"  data-wpil-monitor-id=\"50111\">exploit of this vulnerability<\/a> might look. This pseudocode demonstrates the <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2023-35704-critical-buffer-overflow-vulnerabilities-in-gtkwave-s-fst-leb128-varint-functionality\/\"  data-wpil-monitor-id=\"41723\">overflow occurring when a maliciously oversized .fst<\/a> file is loaded:<\/p>\n<pre><code class=\"\" data-line=\"\"># Pseudocode\ndef load_fst_file(file):\nwith open(file, &#039;r&#039;) as f:\ndata = f.read()\nreturn fastlz_decompress(data)\n# Exploit\nmalicious_fst = generate_oversized_fst()  # A function that generates a malicious .fst file\nload_fst_file(malicious_fst)<\/code><\/pre>\n<p>In this example, the `load_fst_file` function <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2024-48766-critical-unauthenticated-file-reading-vulnerability-in-netalertx\/\"  data-wpil-monitor-id=\"50110\">reads a file<\/a> and then decompresses it using the `fastlz_decompress` function. If a maliciously oversized .fst file is loaded, it could cause a buffer overflow and potentially allow <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2024-40446-arbitrary-code-execution-vulnerability-in-forkosh-mime-tex\/\"  data-wpil-monitor-id=\"39851\">arbitrary code execution<\/a>.<br \/>\nPlease note that this is a highly simplified representation of the actual process and is meant only to provide a conceptual understanding of how such an exploit might work.<\/p>\n<p><strong>Mitigation Guidance<\/strong><\/p>\n<p>Users of affected versions of GTKWave are advised to apply the vendor-supplied patch as soon as possible. If for some reason the patch cannot be applied immediately, a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can provide temporary mitigation by monitoring the traffic and <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2021-40367-critical-vulnerability-in-syngo-fastview-allows-potential-system-compromise\/\"  data-wpil-monitor-id=\"40942\">potentially blocking attempts to exploit this vulnerability<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Overview Security vulnerabilities are a significant concern for software developers and users alike. In this post, we&#8217;ll discuss a particular vulnerability identified as CVE-2023-35956 that impacts the GTKWave software, version 3.3.115. This vulnerability is of serious concern due to its potential to enable arbitrary code execution, leading to potential system compromise or data leakage. GTKWave [&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":[1],"tags":[],"vendor":[],"product":[],"attack_vector":[86,80],"asset_type":[],"severity":[],"exploit_status":[],"class_list":["post-34701","post","type-post","status-publish","format-standard","hentry","category-uncategorized","attack_vector-buffer-overflow","attack_vector-rce"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/34701","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=34701"}],"version-history":[{"count":13,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/34701\/revisions"}],"predecessor-version":[{"id":79846,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/34701\/revisions\/79846"}],"wp:attachment":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/media?parent=34701"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/categories?post=34701"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/tags?post=34701"},{"taxonomy":"vendor","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/vendor?post=34701"},{"taxonomy":"product","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/product?post=34701"},{"taxonomy":"attack_vector","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/attack_vector?post=34701"},{"taxonomy":"asset_type","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/asset_type?post=34701"},{"taxonomy":"severity","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/severity?post=34701"},{"taxonomy":"exploit_status","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/exploit_status?post=34701"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}