{"id":"CVE-2023-4255","aliases":["DEBIAN-CVE-2023-4255","EUVD-2023-54126","GHSA-hx3r-ph4g-9px9","MGASA-2024-0105","SUSE-SU-2024:0014-1","UBUNTU-CVE-2023-4255","USN-6580-1"],"status":"published","title":"W3m: out-of-bounds write in function checktype() in etc.c (incomplete fix for cve-2022-38223)","description":"An out-of-bounds write issue has been discovered in the backspace handling of the checkType() function in etc.c within the W3M application. This vulnerability is triggered by supplying a specially crafted HTML file to the w3m binary. Exploitation of this flaw could lead to application crashes, resulting in a denial of service condition.","severity":{"version":"3.1","score":5.5,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.00322,"percentile":0.25382,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-787"],"published":"2023-12-21T16:08:39Z","modified":"2026-10-28T10:35:17Z","fixes":[{"ecosystem":"Debian:13","package":"w3m","fixed_in":["0.5.3+git20230121-2.1"],"sources":["osv"]},{"ecosystem":"Debian:14","package":"w3m","fixed_in":["0.5.3+git20230121-2.1"],"sources":["osv"]},{"ecosystem":"SUSE:Linux Enterprise Server 12 SP5","package":"w3m","fixed_in":["0.5.3.git20161120-161.9.1"],"sources":["osv"]},{"ecosystem":"SUSE:Linux Enterprise Server for SAP Applications 12 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packages for enterprise linux"},{"vendor":"fedora","product":"fedora"},{"vendor":"fedoraproject","product":"extra_packages_for_enterprise_linux"},{"vendor":"fedoraproject","product":"fedora"},{"vendor":"tats","product":"w3m"}],"references":[{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2255207","tags":["issue-tracking","x_refsource_REDHAT","x_transferred","Issue Tracking","Third Party Advisory","report"]},{"url":"https://github.com/tats/w3m/commit/edc602651c506aeeb60544b55534dd1722a340d3","tags":["x_transferred","Patch","fix"]},{"url":"https://github.com/tats/w3m/issues/268","tags":["x_transferred","Exploit","Issue Tracking","Patch","report"]},{"url":"https://github.com/tats/w3m/pull/273","tags":["x_transferred","Issue Tracking","Patch","fix","report"]},{"url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/AULOBQJLXE2KCT5UVQMKGEFL4GFIAOED/","tags":["x_transferred","web"]},{"url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/TODROGVCWZ435HQIZE6ARQC5LPQLIA5C/","tags":["x_transferred","web"]},{"url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/MKFZQUK7FPWWJQYICDZZ4YWIPUPQ2D3R/","tags":["x_transferred","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2023-4255","tags":["advisory"]},{"url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/AULOBQJLXE2KCT5UVQMKGEFL4GFIAOED"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/MKFZQUK7FPWWJQYICDZZ4YWIPUPQ2D3R"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/TODROGVCWZ435HQIZE6ARQC5LPQLIA5C"},{"url":"https://github.com/advisories/GHSA-hx3r-ph4g-9px9"},{"url":"https://packages.fedoraproject.org/","tags":["web"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/4xxx/CVE-2023-4255.json","tags":["advisory"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2023-4255","tags":["advisory"]},{"url":"https://advisories.mageia.org/MGASA-2024-0105.html","tags":["advisory"]},{"url":"https://bugs.mageia.org/show_bug.cgi?id=33027","tags":["report"]},{"url":"https://www.suse.com/support/update/announcement/2024/suse-su-20240014-1/","tags":["advisory"]},{"url":"https://bugzilla.suse.com/1218226","tags":["report"]},{"url":"https://www.suse.com/security/cve/CVE-2023-4255","tags":["web"]},{"url":"https://ubuntu.com/security/CVE-2023-4255","tags":["report"]},{"url":"https://ubuntu.com/security/notices/USN-6580-1","tags":["advisory"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2023-4255","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2023-4255","title":"W3m: out-of-bounds write in function checktype() in etc.c (incomplete fix for cve-2022-38223)","description":"An out-of-bounds write issue has been discovered in the backspace handling of the checkType() function in etc.c within the W3M application. This vulnerability is triggered by supplying a specially crafted HTML file to the w3m binary. Exploitation of this flaw could lead to application crashes, resulting in a denial of service condition.","status":"published","published":"2023-12-21T16:08:39.691Z","modified":"2025-02-13T17:09:26.229Z","cvss":[{"version":"3.1","score":5.5,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","level":"medium","assessor":"cna"}],"cwes":["CWE-787"],"updated_at":"2026-11-02T14:35:30.474787Z"}],"euvd":[{"id":"EUVD-2023-54126","description":"An out-of-bounds write issue has been discovered in the backspace handling of the checkType() function in etc.c within the W3M application. This vulnerability is triggered by supplying a specially crafted HTML file to the w3m binary. Exploitation of this flaw could lead to application crashes, resulting in a denial of service condition.","status":"published","published":"2023-12-21T16:08:39Z","modified":"2025-02-13T17:09:26Z","cvss":[{"version":"3.1","score":5.5,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","level":"medium"}],"updated_at":"2026-11-03T00:03:49.098775Z"}],"ghsa":[{"id":"GHSA-hx3r-ph4g-9px9","title":"An out-of-bounds write issue has been discovered in the backspace handling of the checkType()...","description":"An out-of-bounds write issue has been discovered in the backspace handling of the checkType() function in etc.c within the W3M application. This vulnerability is triggered by supplying a specially crafted HTML file to the w3m binary. Exploitation of this flaw could lead to application crashes, resulting in a denial of service condition.","status":"published","published":"2023-12-21T18:30:23Z","modified":"2024-03-27T03:31:17Z","cvss":[{"version":"3.1","score":5.5,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","level":"medium"}],"cwes":["CWE-787"],"updated_at":"2026-11-02T14:55:43.067988Z"}],"nvd":[{"id":"CVE-2023-4255","description":"An out-of-bounds write issue has been discovered in the backspace handling of the checkType() function in etc.c within the W3M application. This vulnerability is triggered by supplying a specially crafted HTML file to the w3m binary. Exploitation of this flaw could lead to application crashes, resulting in a denial of service condition.","status":"published","published":"2023-12-21T16:15:10.017Z","modified":"2026-06-17T06:37:25.357Z","cvss":[{"version":"3.1","score":5.5,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","level":"medium","assessor":"secondary"},{"version":"3.1","score":5.5,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","level":"medium","assessor":"primary"}],"cwes":["CWE-787"],"updated_at":"2026-11-02T14:08:57.117371Z"}],"osv":[{"id":"CVE-2023-4255","title":"W3m: out-of-bounds write in function checktype() in etc.c (incomplete fix for cve-2022-38223)","description":"An out-of-bounds write issue has been discovered in the backspace handling of the checkType() function in etc.c within the W3M application. This vulnerability is triggered by supplying a specially crafted HTML file to the w3m binary. Exploitation of this flaw could lead to application crashes, resulting in a denial of service condition.","status":"published","published":"2023-12-21T16:08:39.691Z","modified":"2026-10-28T10:35:17.896111Z","cvss":[{"version":"3.1","score":5.5,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","level":"medium"}],"cwes":["CWE-787"],"updated_at":"2026-11-02T15:44:33.792101Z"},{"id":"DEBIAN-CVE-2023-4255","description":"An out-of-bounds write issue has been discovered in the backspace handling of the checkType() function in etc.c within the W3M application. This vulnerability is triggered by supplying a specially crafted HTML file to the w3m binary. Exploitation of this flaw could lead to application crashes, resulting in a denial of service condition.","status":"published","published":"2023-12-21T16:15:10.017Z","modified":"2026-10-26T18:02:33.015524621Z","cvss":[{"version":"3.1","score":5.5,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","level":"medium"}],"updated_at":"2026-11-02T15:45:40.275853Z"},{"id":"UBUNTU-CVE-2023-4255","description":"An out-of-bounds write issue has been discovered in the backspace handling of the checkType() function in etc.c within the W3M application. This vulnerability is triggered by supplying a specially crafted HTML file to the w3m binary. Exploitation of this flaw could lead to application crashes, resulting in a denial of service condition.","status":"published","published":"2024-01-02T00:00:00Z","modified":"2026-02-04T03:02:34.387932Z","cvss":[{"version":"3.1","score":5.5,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","level":"medium"},{"version":"3.1","score":5.5,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","level":"medium"}],"updated_at":"2026-11-02T16:54:22.741943Z"},{"id":"MGASA-2024-0105","title":"Updated w3m packages fix security vulnerabilities","description":"An out-of-bounds read flaw was found in w3m, in the Strnew_size function\nin Str.c. This issue may allow an attacker to cause a denial of service\nthrough a crafted HTML file. (CVE-2023-38252)\nAn out-of-bounds read flaw was found in w3m, in the growbuf_to_Str\nfunction in indep.c. This issue may allow an attacker to cause a denial\nof service through a crafted HTML file. (CVE-2023-38253)\nAn out-of-bounds write issue has been discovered in the backspace\nhandling of the checkType() function in etc.c within the W3M\napplication. This vulnerability is triggered by supplying a specially\ncrafted HTML file to the w3m binary. Exploitation of this flaw could\nlead to application crashes, resulting in a denial of service condition.\n(CVE-2023-4255)\n","status":"published","published":"2024-04-01T19:50:27Z","modified":"2026-04-16T04:42:54.700418957Z","updated_at":"2026-11-02T15:49:42.684501Z"},{"id":"SUSE-SU-2024:0014-1","title":"Security update for w3m","description":"This update for w3m fixes the following issues:\n\n- CVE-2023-4255: Fixed out-of-bounds write in function checkType() in etc.c (bsc#1218226).\n","status":"published","published":"2024-01-02T17:51:48Z","modified":"2026-02-04T04:15:25.32372Z","updated_at":"2026-11-02T15:53:53.865042Z"},{"id":"USN-6580-1","title":"w3m vulnerability","description":"It was discovered that w3m incorrectly handled certain HTML files.\nAn attacker could possibly use this issue to cause a crash or\nexecute arbitrary code.\n","status":"published","published":"2024-01-15T11:45:46Z","modified":"2026-06-29T13:51:00.631411509Z","updated_at":"2026-11-02T16:58:17.305935Z"}]}}