Advisory Details

September 10th, 2020

Microsoft Excel XLS File Parsing Use-After-Free Remote Code Execution Vulnerability

ZDI-20-1132
ZDI-CAN-11276

CVE ID CVE-2020-1193
CVSS SCORE 5.3, AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L
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. Crafted data in an XLS file can cause a pointer to be reused after it has been freed. An attacker can leverage this vulnerability to execute code in the context of the current process at low integrity.

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-2020-1193
DISCLOSURE TIMELINE
  • 2020-07-02 - Vulnerability reported to vendor
  • 2020-09-10 - Coordinated public release of advisory
CREDIT ecN4L
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