Medium severity · published Sep 9, 2022
CVE-2021-40647
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
5.5
CVSS
0.3%
EPSS
No
On KEV
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 vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
Attack vector
Local
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 26% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
MA
Man2html · Man2html Project
1.6g · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-40647
CVE.org
https://www.cve.org/CVERecord?id=CVE-2021-40647
Exploit
https://gist.github.com/untaman/cb58123fe89fc65e3984165db5d40933
More from Man2html
5.5
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