{"api_version":"1","generated_at":"2026-07-23T12:11:40+00:00","cve":"CVE-2021-40647","urls":{"html":"https://cve.report/CVE-2021-40647","api":"https://cve.report/api/cve/CVE-2021-40647.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2021-40647","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2021-40647"},"summary":{"title":"CVE-2021-40647","description":"In man2html 1.6g, a specific string being read in from a file will overwrite the size parameter in the top chunk of the heap. This at least causes the program to segmentation abort if the heap size parameter isn't aligned correctly. In version before GLIBC version 2.29 and aligned correctly, it allows arbitrary write anywhere in the programs memory.","state":"PUBLIC","assigner":"cve@mitre.org","published_at":"2022-09-09 18:15:00","updated_at":"2023-08-08 14:22:00"},"problem_types":["CWE-787"],"metrics":[],"references":[{"url":"https://gist.github.com/untaman/cb58123fe89fc65e3984165db5d40933","name":"https://gist.github.com/untaman/cb58123fe89fc65e3984165db5d40933","refsource":"MISC","tags":[],"title":"CVE-2021-40647 and CVE-2021-40648   · GitHub","mime":"text/html","httpstatus":"200","archivestatus":"404"},{"url":"http://man2html.com","name":"http://man2html.com","refsource":"MISC","tags":[],"title":"","mime":"","httpstatus":"-1","archivestatus":"404"},{"url":"http://na.com","name":"http://na.com","refsource":"MISC","tags":[],"title":"Commercial Distributor & Supply Company | North American","mime":"text/html","httpstatus":"200","archivestatus":"200"},{"url":"https://www.cve.org/CVERecord?id=CVE-2021-40647","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-40647","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[{"cve_year":"2021","cve_id":"40647","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"a","cpe4":"man2html_project","cpe5":"man2html","cpe6":"1.6g","cpe7":"*","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"}],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"CVE_data_meta":{"ASSIGNER":"cve@mitre.org","ID":"CVE-2021-40647","STATE":"PUBLIC"},"affects":{"vendor":{"vendor_data":[{"product":{"product_data":[{"product_name":"n/a","version":{"version_data":[{"version_value":"n/a"}]}}]},"vendor_name":"n/a"}]}},"data_format":"MITRE","data_type":"CVE","data_version":"4.0","description":{"description_data":[{"lang":"eng","value":"In man2html 1.6g, a specific string being read in from a file will overwrite the size parameter in the top chunk of the heap. This at least causes the program to segmentation abort if the heap size parameter isn't aligned correctly. In version before GLIBC version 2.29 and aligned correctly, it allows arbitrary write anywhere in the programs memory."}]},"problemtype":{"problemtype_data":[{"description":[{"lang":"eng","value":"n/a"}]}]},"references":{"reference_data":[{"refsource":"MISC","name":"https://gist.github.com/untaman/cb58123fe89fc65e3984165db5d40933","url":"https://gist.github.com/untaman/cb58123fe89fc65e3984165db5d40933"}]}},"nvd":{"publishedDate":"2022-09-09 18:15:00","lastModifiedDate":"2023-08-08 14:22:00","problem_types":["CWE-787"],"metrics":{"baseMetricV3":{"cvssV3":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"REQUIRED","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH","baseScore":5.5,"baseSeverity":"MEDIUM"},"exploitabilityScore":1.8,"impactScore":3.6}},"configurations":{"CVE_data_version":"4.0","nodes":[{"operator":"OR","children":[],"cpe_match":[{"vulnerable":true,"cpe23Uri":"cpe:2.3:a:man2html_project:man2html:1.6g:*:*:*:*:*:*:*","cpe_name":[]}]}]}},"legacy_mitre":{"record":{"CveYear":"2021","CveId":"40647","Ordinal":"216396","Title":"CVE-2021-40647","CVE":"CVE-2021-40647","Year":"2021"},"notes":[{"CveYear":"2021","CveId":"40647","Ordinal":"1","NoteData":"** RESERVED ** This candidate has been reserved by an organization or individual that will use it when announcing a new security problem. When the candidate has been publicized, the details for this candidate will be provided.","Type":"Description","Title":null}]}}}