Integer overflow in cmark-gfm table parsing extension leads to heap memory corruption
High severity
GitHub Reviewed
Published
Mar 3, 2022
in
gjtorikian/commonmarker
•
Updated Jan 8, 2024
Description
Published to the GitHub Advisory Database
Mar 3, 2022
Reviewed
Mar 3, 2022
Last updated
Jan 8, 2024
Impact
CommonMarker uses
cmark-gfm
for rendering Github Flavored Markdown. An integer overflow incmark-gfm
's table row parsing may lead to heap memory corruption when parsing tables who's marker rows contain more than UINT16_MAX columns. The impact of this heap corruption ranges from Information Leak to Arbitrary Code Execution.If affected versions of CommonMarker are used for rendering remote user controlled markdown, this vulnerability may lead to Remote Code Execution (RCE).
Patches
This vulnerability has been patched in the following CommonMarker release:
Workarounds
The vulnerability exists in the table markdown extensions of
cmark-gfm
. Disabling any use of the table extension will prevent this vulnerability from being triggered.References
Acknowledgements
We would like to thank Felix Wilhelm of Google's Project Zero for reporting this vulnerability
For more information
If you have any questions or comments about this advisory:
References