Advisory Details

October 14th, 2021

Microsoft Office Word Converter Use-After-Free Remote Code Execution Vulnerability

ZDI-21-1158
ZDI-CAN-14203

CVE ID CVE-2021-40486
CVSS SCORE 7.8, AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
AFFECTED VENDORS Microsoft
AFFECTED PRODUCTS Office
VULNERABILITY DETAILS

This vulnerability allows remote attackers to execute arbitrary code on affected installations of Microsoft Office. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file.

The specific flaw exists within the parsing of DOC files. The issue results from the lack of validating the existence of an object prior to performing operations on the object. An attacker can leverage this vulnerability to execute code in the context of the current process.

ADDITIONAL DETAILS Microsoft has issued an update to correct this vulnerability. More details can be found at:
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-40486
DISCLOSURE TIMELINE
  • 2021-07-13 - Vulnerability reported to vendor
  • 2021-10-14 - Coordinated public release of advisory
CREDIT kdot
BACK TO ADVISORIES