An exploitable sign extension vulnerability exists in the TextMaker document parsing functionality of SoftMaker Office 2021’s TextMaker application. A specially crafted document can cause the document parser to sign-extend a length used to terminate a loop, which can later result in the loop’s index being used to write outside the bounds of a heap buffer during the reading of file data. An attacker can entice the victim to open a document to trigger this vulnerability.
The product performs an operation on a number that causes it to be sign extended when it is transformed into a larger data type. When the original number is negative, this can produce unexpected values that lead to resultant weaknesses.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Softmaker_office | Softmaker | 2021 (including) | 2021 (including) |