{"cve":"CVE-2021-40647","nvd":{"published":"2022-09-09T18:15:09.197","modified":"2026-06-17T04:07:12.840","status":"Modified","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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-787"],"references":["https://gist.github.com/untaman/cb58123fe89fc65e3984165db5d40933","https://gist.github.com/untaman/cb58123fe89fc65e3984165db5d40933"],"products":["man2html_project:man2html"],"source":"nvd","synced_at":"2026-10-19T21:35:14.992143698+00:00"},"epss":{"cve":"CVE-2021-40647","score":0.00333,"percentile":0.26526,"date":"2026-11-01"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}