CVE-2021-40648
In man2html 1.6g, a filename can be created to overwrite the previous size parameter of the next...
In man2html 1.6g, a filename can be created to overwrite the previous size parameter of the next chunk and the fd, bk, fd_nextsize, bk_nextsize of the current chunk. The next chunk is then freed later on, causing a freeing of an arbitrary amount of memory.
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
In man2html 1.6g, a filename can be created to overwrite the previous size parameter of the next chunk and the fd, bk, fd_nextsize, bk_nextsize of the current chunk. The next chunk is then freed later on, causing a freeing of an arbitrary amount of memory.
- Record
CVE-2021-40648- CVSS 3.1
- 5.5 Medium
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H - Weakness
- CWE-20
- Updated
- 2026-11-02
CVE List No score
In man2html 1.6g, a filename can be created to overwrite the previous size parameter of the next chunk and the fd, bk, fd_nextsize, bk_nextsize of the current chunk. The next chunk is then freed later on, causing a freeing of an arbitrary amount of memory.
- Record
CVE-2021-40648- Updated
- 2026-11-02
EUVDEUVD-2021-27822 No score
In man2html 1.6g, a filename can be created to overwrite the previous size parameter of the next chunk and the fd, bk, fd_nextsize, bk_nextsize of the current chunk. The next chunk is then freed later on, causing a freeing of an arbitrary amount of memory.
- Record
EUVD-2021-27822- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-x62g-3vp2-7m3v
In man2html 1.6g, a filename can be created to overwrite the previous size parameter of the next...
In man2html 1.6g, a filename can be created to overwrite the previous size parameter of the next chunk and the fd, bk, fd_nextsize, bk_nextsize of the current chunk. The next chunk is then freed later on, causing a freeing of an arbitrary amount of memory.
- Record
GHSA-x62g-3vp2-7m3v- CVSS 3.1
- 5.5 Medium
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H - Weakness
- CWE-20
- Updated
- 2026-11-02
OSV
In man2html 1.6g, a filename can be created to overwrite the previous size parameter of the next chunk and the fd, bk, fd_nextsize, bk_nextsize of the current chunk. The next chunk is then freed later on, causing a freeing of an arbitrary amount of memory.
- Record
CVE-2021-40648- CVSS 3.1
- 5.5 Medium
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVDEBIAN-CVE-2021-40648
In man2html 1.6g, a filename can be created to overwrite the previous size parameter of the next chunk and the fd, bk, fd_nextsize, bk_nextsize of the current chunk. The next chunk is then freed later on, causing a freeing of an arbitrary amount of memory.
- Record
DEBIAN-CVE-2021-40648- CVSS 3.1
- 5.5 Medium
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVUBUNTU-CVE-2021-40648
In man2html 1.6g, a filename can be created to overwrite the previous size parameter of the next chunk and the fd, bk, fd_nextsize, bk_nextsize of the current chunk. The next chunk is then freed later on, causing a freeing of an arbitrary amount of memory.
- Record
UBUNTU-CVE-2021-40648- CVSS 3.1
- 5.5 Medium
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
man2htmlDebian:12 |
All versions, plus listed versions 1.6g-141.6g-151.6g-16 |
None known |
man2htmlDebian:13 |
All versions, plus listed versions 1.6g-16 |
None known |
man2htmlDebian:14 |
All versions, plus listed versions 1.6g-16 |
None known |
man2htmlUbuntu:16.04:LTS |
All versions, plus listed versions 1.6g-71.6g-8 |
None known |
man2htmlUbuntu:18.04:LTS |
All versions, plus listed versions 1.6g-91.6g-9ubuntu11.6g-11 |
None known |
man2htmlUbuntu:20.04:LTS |
All versions, plus listed versions 1.6g-12 |
None known |
man2htmlUbuntu:22.04:LTS |
All versions, plus listed versions 1.6g-14 |
None known |
man2htmlUbuntu:24.04:LTS |
All versions, plus listed versions 1.6g-141.6g-151.6g-16 |
None known |
man2htmlUbuntu:25.10 |
All versions, plus listed versions 1.6g-16 |
None known |
man2htmlUbuntu:26.10 |
All versions, plus listed versions 1.6g-16build1 |
None known |
man2htmlUbuntu:26.04:LTS |
All versions, plus listed versions 1.6g-161.6g-16build1 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-40648 is a medium vulnerability (CVSS 5.5) in Man2html Project Man2html, published September 9, 2022. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.34%, the 27th percentile. No source names a fixed version.