# CVE-2021-40647: man2html: In man2html 1.6g, a specific string being read in from a file will overwrite the size parameter in the top chunk of t...

CVE-2021-40647 is fixed in man2html on 1 platform, first by DEBIAN-CVE-2021-40647, released September 9, 2022. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2021-40647
- Priority: Routine
- CVSS: 5.5 (medium)
- EPSS: 0.0034
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Sep 9, 2022

## 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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | man2html Debian 13.5 (trixie) | 1.6g-16 | [DEBIAN-CVE-2021-40647](https://patchblox.com/security/data/fix/linux/debian-cve-2021-40647.md) | Sep 9, 2022 |
| Linux | man2html Debian 14 | 1.6g-16 | [DEBIAN-CVE-2021-40647](https://patchblox.com/security/data/fix/linux/debian-cve-2021-40647.md) | Sep 9, 2022 |

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