Advisory Details

October 19th, 2020

Microsoft Excel XLS File Parsing Out-Of-Bounds Write Remote Code Execution Vulnerability

ZDI-20-1256
ZDI-CAN-11602

CVE ID CVE-2020-16930
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 Excel
VULNERABILITY DETAILS

This vulnerability allows remote attackers to execute arbitrary code on affected installations of Microsoft Excel. 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 XLS files. The issue results from the lack of proper validation of user-supplied data, which can result in a write past the end of an allocated buffer. 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://portal.msrc.microsoft.com/en-us/security-guidance/advisory/CVE-2020-16930
DISCLOSURE TIMELINE
  • 2020-08-12 - Vulnerability reported to vendor
  • 2020-10-19 - Coordinated public release of advisory
CREDIT kdot
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