{"id":"CVE-2021-28040","aliases":["EUVD-2021-14747","GHSA-87rm-8q5w-499g"],"status":"published","title":"An issue was discovered in OSSEC 3.6.0. An uncontrolled recursion vulnerability in os_xml.c...","description":"An issue was discovered in OSSEC 3.6.0. An uncontrolled recursion vulnerability in os_xml.c occurs when a large number of opening and closing XML tags is used. Because recursion is used in _ReadElem without restriction, an attacker can trigger a segmentation fault once unmapped memory is reached.","severity":{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-09","score":0.01192,"percentile":0.68218,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-674"],"published":"2021-03-05T17:46:34Z","modified":"2026-10-20T10:54:35Z","products":[{"vendor":"ossec","product":"ossec"}],"references":[{"url":"https://github.com/ossec/ossec-hids/issues/1953","tags":["x_refsource_MISC","x_transferred","Exploit","Issue Tracking","Third Party Advisory","report"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-28040"},{"url":"https://github.com/advisories/GHSA-87rm-8q5w-499g"}],"sources":{"cve":[{"id":"CVE-2021-28040","description":"An issue was discovered in OSSEC 3.6.0. An uncontrolled recursion vulnerability in os_xml.c occurs when a large number of opening and closing XML tags is used. Because recursion is used in _ReadElem without restriction, an attacker can trigger a segmentation fault once unmapped memory is reached.","status":"published","published":"2021-03-05T17:46:34Z","modified":"2024-08-03T21:33:17.414Z","updated_at":"2026-11-02T14:33:09.175141Z"}],"euvd":[{"id":"EUVD-2021-14747","description":"An issue was discovered in OSSEC 3.6.0. An uncontrolled recursion vulnerability in os_xml.c occurs when a large number of opening and closing XML tags is used. Because recursion is used in _ReadElem without restriction, an attacker can trigger a segmentation fault once unmapped memory is reached.","status":"published","published":"2021-03-05T17:46:34Z","modified":"2024-08-03T21:33:17Z","updated_at":"2026-11-03T03:24:47.80549Z"}],"ghsa":[{"id":"GHSA-87rm-8q5w-499g","title":"An issue was discovered in OSSEC 3.6.0. An uncontrolled recursion vulnerability in os_xml.c...","description":"An issue was discovered in OSSEC 3.6.0. An uncontrolled recursion vulnerability in os_xml.c occurs when a large number of opening and closing XML tags is used. Because recursion is used in _ReadElem without restriction, an attacker can trigger a segmentation fault once unmapped memory is reached.","status":"published","published":"2022-05-24T17:43:48Z","modified":"2023-01-29T05:06:45Z","cwes":["CWE-674"],"updated_at":"2026-11-02T14:46:05.419939Z"}],"nvd":[{"id":"CVE-2021-28040","description":"An issue was discovered in OSSEC 3.6.0. An uncontrolled recursion vulnerability in os_xml.c occurs when a large number of opening and closing XML tags is used. Because recursion is used in _ReadElem without restriction, an attacker can trigger a segmentation fault once unmapped memory is reached.","status":"published","published":"2021-03-05T18:15:13.27Z","modified":"2026-06-17T03:45:45.963Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"primary"},{"version":"2.0","score":5,"vector":"AV:N/AC:L/Au:N/C:N/I:N/A:P","level":"medium","assessor":"primary"}],"cwes":["CWE-674"],"updated_at":"2026-11-02T14:06:50.399901Z"}],"osv":[{"id":"CVE-2021-28040","description":"An issue was discovered in OSSEC 3.6.0. An uncontrolled recursion vulnerability in os_xml.c occurs when a large number of opening and closing XML tags is used. Because recursion is used in _ReadElem without restriction, an attacker can trigger a segmentation fault once unmapped memory is reached.","status":"published","published":"2021-03-05T18:15:13.27Z","modified":"2026-10-20T10:54:35.74842453Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-02T15:44:19.129331Z"}]}}