{"id":"CVE-2021-34121","aliases":["DEBIAN-CVE-2021-34121","EUVD-2021-20784","GHSA-vvmp-35v7-f6q6","UBUNTU-CVE-2021-34121","USN-7189-1"],"status":"published","title":"An Out of Bounds flaw was discovered in htmodoc 1.9.12 in function parse_tree() in toc.cxx, this...","description":"An Out of Bounds flaw was discovered in htmodoc 1.9.12 in function parse_tree() in toc.cxx, this possibly leads to memory layout information leaking in the data. This might be used in a chain of vulnerability in order to reach code execution.","severity":{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-10","score":0.00336,"percentile":0.27238,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-125"],"published":"2023-07-18T00:00:00Z","modified":"2026-10-23T18:03:49Z","fixes":[{"ecosystem":"Debian:12","package":"htmldoc","fixed_in":["1.9.13-1"],"sources":["osv"]},{"ecosystem":"Debian:13","package":"htmldoc","fixed_in":["1.9.13-1"],"sources":["osv"]},{"ecosystem":"Debian:14","package":"htmldoc","fixed_in":["1.9.13-1"],"sources":["osv"]},{"ecosystem":"Ubuntu:Pro:14.04:LTS","package":"htmldoc","fixed_in":["1.8.27-8ubuntu1+esm3"],"sources":["osv"]},{"ecosystem":"Ubuntu:Pro:16.04:LTS","package":"htmldoc","fixed_in":["1.8.27-8ubuntu1.1+esm2"],"sources":["osv"]},{"ecosystem":"Ubuntu:Pro:18.04:LTS","package":"htmldoc","fixed_in":["1.9.2-1ubuntu0.2+esm1"],"sources":["osv"]},{"ecosystem":"Ubuntu:Pro:20.04:LTS","package":"htmldoc","fixed_in":["1.9.7-1ubuntu0.3+esm1"],"sources":["osv"]}],"affected":[{"source":"osv","ecosystem":"Debian:12","package":"htmldoc","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.9.13-1"}]}]},{"source":"osv","ecosystem":"Debian:13","package":"htmldoc","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.9.13-1"}]}]},{"source":"osv","ecosystem":"Debian:14","package":"htmldoc","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.9.13-1"}]}]},{"source":"osv","ecosystem":"Ubuntu:Pro:14.04:LTS","package":"htmldoc","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.8.27-8ubuntu1+esm3"}]}],"versions":["1.8.27-8ubuntu1","1.8.27-8ubuntu1+esm1","1.8.27-8ubuntu1+esm2"]},{"source":"osv","ecosystem":"Ubuntu:Pro:16.04:LTS","package":"htmldoc","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.8.27-8ubuntu1.1+esm2"}]}],"versions":["1.8.27-8ubuntu1","1.8.27-8ubuntu1.1","1.8.27-8ubuntu1.1+esm1"]},{"source":"osv","ecosystem":"Ubuntu:Pro:18.04:LTS","package":"htmldoc","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.9.2-1ubuntu0.2+esm1"}]}],"versions":["1.8.27-8ubuntu2","1.8.27-8ubuntu3","1.9.2-1","1.9.2-1ubuntu0.1","1.9.2-1ubuntu0.2"]},{"source":"osv","ecosystem":"Ubuntu:Pro:20.04:LTS","package":"htmldoc","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.9.7-1ubuntu0.3+esm1"}]}],"versions":["1.9.3-1","1.9.7-1","1.9.7-1build1","1.9.7-1ubuntu0.2","1.9.7-1ubuntu0.3"]},{"source":"osv","ecosystem":"Ubuntu:Pro:14.04:LTS","package":"htmldoc","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.8.27-8ubuntu1+esm3"}]}],"versions":["1.8.27-8ubuntu1","1.8.27-8ubuntu1+esm1","1.8.27-8ubuntu1+esm2"],"bundled":11},{"source":"osv","ecosystem":"Ubuntu:Pro:16.04:LTS","package":"htmldoc","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.8.27-8ubuntu1.1+esm2"}]}],"versions":["1.8.27-8ubuntu1","1.8.27-8ubuntu1.1","1.8.27-8ubuntu1.1+esm1"],"bundled":11},{"source":"osv","ecosystem":"Ubuntu:Pro:18.04:LTS","package":"htmldoc","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.9.2-1ubuntu0.2+esm1"}]}],"versions":["1.8.27-8ubuntu2","1.8.27-8ubuntu3","1.9.2-1","1.9.2-1ubuntu0.1","1.9.2-1ubuntu0.2"],"bundled":11},{"source":"osv","ecosystem":"Ubuntu:Pro:20.04:LTS","package":"htmldoc","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.9.7-1ubuntu0.3+esm1"}]}],"versions":["1.9.3-1","1.9.7-1","1.9.7-1build1","1.9.7-1ubuntu0.2","1.9.7-1ubuntu0.3"],"bundled":11}],"products":[{"vendor":"htmldoc_project","product":"htmldoc"}],"references":[{"url":"https://github.com/michaelrsweet/htmldoc/issues/433","tags":["x_transferred","Exploit","Issue Tracking","report"]},{"url":"https://github.com/michaelrsweet/htmldoc/commit/c67bbd8756f015e33e4ba639a40c7f9d8bd9e8ab","tags":["x_transferred","Patch","fix","report"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-34121"},{"url":"https://github.com/advisories/GHSA-vvmp-35v7-f6q6"},{"url":"https://security-tracker.debian.org/tracker/CVE-2021-34121","tags":["advisory"]},{"url":"https://ubuntu.com/security/CVE-2021-34121","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2021-34121","tags":["report"]},{"url":"https://ubuntu.com/security/notices/USN-7189-1","tags":["advisory"]},{"url":"https://ubuntu.com/security/CVE-2021-20308","tags":["report"]},{"url":"https://ubuntu.com/security/CVE-2021-23158","tags":["report"]},{"url":"https://ubuntu.com/security/CVE-2021-23191","tags":["report"]},{"url":"https://ubuntu.com/security/CVE-2021-23206","tags":["report"]},{"url":"https://ubuntu.com/security/CVE-2021-26252","tags":["report"]},{"url":"https://ubuntu.com/security/CVE-2021-26259","tags":["report"]},{"url":"https://ubuntu.com/security/CVE-2021-26948","tags":["report"]},{"url":"https://ubuntu.com/security/CVE-2021-34119","tags":["report"]},{"url":"https://ubuntu.com/security/CVE-2021-40985","tags":["report"]},{"url":"https://ubuntu.com/security/CVE-2021-43579","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2021-34121","description":"An Out of Bounds flaw was discovered in htmodoc 1.9.12 in function parse_tree() in toc.cxx, this possibly leads to memory layout information leaking in the data. This might be used in a chain of vulnerability in order to reach code execution.","status":"published","published":"2023-07-18T00:00:00Z","modified":"2024-10-28T17:04:36.328Z","updated_at":"2026-11-02T14:33:11.244759Z"}],"euvd":[{"id":"EUVD-2021-20784","description":"An Out of Bounds flaw was discovered in htmodoc 1.9.12 in function parse_tree() in toc.cxx, this possibly leads to memory layout information leaking in the data. This might be used in a chain of vulnerability in order to reach code execution.","status":"published","published":"2023-07-18T00:00:00Z","modified":"2024-10-28T17:04:36Z","updated_at":"2026-11-03T00:05:16.135425Z"}],"ghsa":[{"id":"GHSA-vvmp-35v7-f6q6","title":"An Out of Bounds flaw was discovered in htmodoc 1.9.12 in function parse_tree() in toc.cxx, this...","description":"An Out of Bounds flaw was discovered in htmodoc 1.9.12 in function parse_tree() in toc.cxx, this possibly leads to memory layout information leaking in the data. This might be used in a chain of vulnerability in order to reach code execution.","status":"published","published":"2023-07-18T15:30:36Z","modified":"2024-04-04T06:13:22Z","cvss":[{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high"}],"cwes":["CWE-125"],"updated_at":"2026-11-02T14:56:40.370348Z"}],"nvd":[{"id":"CVE-2021-34121","description":"An Out of Bounds flaw was discovered in htmodoc 1.9.12 in function parse_tree() in toc.cxx, this possibly leads to memory layout information leaking in the data. This might be used in a chain of vulnerability in order to reach code execution.","status":"published","published":"2023-07-18T14:15:11.78Z","modified":"2026-06-17T03:55:29.587Z","cvss":[{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high","assessor":"primary"}],"cwes":["CWE-125"],"updated_at":"2026-11-02T14:07:07.764332Z"}],"osv":[{"id":"CVE-2021-34121","description":"An Out of Bounds flaw was discovered in htmodoc 1.9.12 in function parse_tree() in toc.cxx, this possibly leads to memory layout information leaking in the data. This might be used in a chain of vulnerability in order to reach code execution.","status":"published","published":"2023-07-18T14:15:11.78Z","modified":"2026-10-20T14:23:27.174863089Z","cvss":[{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high"}],"updated_at":"2026-11-02T15:44:20.13324Z"},{"id":"DEBIAN-CVE-2021-34121","description":"An Out of Bounds flaw was discovered in htmodoc 1.9.12 in function parse_tree() in toc.cxx, this possibly leads to memory layout information leaking in the data. This might be used in a chain of vulnerability in order to reach code execution.","status":"published","published":"2023-07-18T14:15:11.78Z","modified":"2026-10-23T18:03:49.564113711Z","cvss":[{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high"}],"updated_at":"2026-11-02T15:45:35.233346Z"},{"id":"UBUNTU-CVE-2021-34121","description":"An Out of Bounds flaw was discovered in htmodoc 1.9.12 in function parse_tree() in toc.cxx, this possibly leads to memory layout information leaking in the data. This might be used in a chain of vulnerability in order to reach code execution.","status":"published","published":"2023-07-18T14:15:00Z","modified":"2026-02-04T02:56:02.355831Z","cvss":[{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high"}],"updated_at":"2026-11-02T15:54:27.870979Z"},{"id":"USN-7189-1","title":"HTMLDOC vulnerabilities","description":"It was discovered that HTMLDOC incorrectly handled certain inputs, which\ncould lead to an integer overflow. An attacker could potentially use this\nissue to cause a denial of service or execute arbitrary code.\n(CVE-2021-20308)\n\nIt was discovered that HTMLDOC incorrectly handled memory in pspdf_export,\nwhich could lead to a double-free. An attacker could potentially use this\nissue to cause a denial of service or execute arbitrary code.\n(CVE-2021-23158)\n\nIt was discovered that HTMLDOC incorrectly handled memory when loading a\nJPEG image, which could lead to a NULL pointer dereference. An attacker\ncould potentially use this issue to cause a denial of service.\n(CVE-2021-23191, CVE-2021-26948)\n\nIt was discovered that HTMLDOC incorrectly handled certain inputs, which\ncould lead to a stack buffer overflow. An attacker could potentially use\nthis issue to cause a denial of service or execute arbitrary code.\n(CVE-2021-23206, CVE-2021-40985, CVE-2021-43579)\n\nIt was discovered that HTMLDOC incorrectly handled memory in\npdpdf_prepare_page and render_table_row, which could lead to a heap buffer\noverflow. An attacker could potentially use this issue to cause a denial\nof service or execute arbitrary code. (CVE-2021-26252, CVE-2021-26259)\n\nIt was discovered that HTMLDOC incorrectly handled memory in\nparse_paragraph, which could lead to a heap buffer overflow. An attacker\ncould potentially use this issue to cause a denial of service or execute\narbitrary code. This issue only affected Ubuntu 20.04 LTS. (CVE-2021-34119)\n\nIt was discovered that HTMLDOC incorrectly handled memory in parse_tree.\nAn attacker could potentially use this issue to leak sensitive\ninformation. (CVE-2021-34121)\n","status":"published","published":"2025-01-08T01:23:50Z","modified":"2026-06-25T13:32:29.997721461Z","updated_at":"2026-11-02T16:58:18.876384Z"}]}}