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.

References

• https://nvd.nist.gov/vuln/detail/CVE-2020-13545
• https://talosintelligence.com/vulnerability_reports/TALOS-2020-1162