CVE-2020-13545: Unsigned to Signed Conversion Error

An exploitable signed conversion 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 miscalculate a length used to allocate a buffer, later upon usage of this buffer the application will write outside its bounds resulting in a heap-based memory corruption. An attacker can entice the victim to open a document to trigger this vulnerability.