CVE-2020-1493 — Microsoft Outlook Information Disclosure Vulnerability

Executive Summary

An information disclosure vulnerability exists when attaching files to Outlook messages. This vulnerability could potentially allow users to share attached files such that they are accessible by anonymous users where they should be restricted to specific users. To exploit this vulnerability, an attacker would have to attach a file as a link to an email. The email could then be shared with individuals that should not have access to the files, ignoring the default organizational setting. The security update addresses the vulnerability by correcting how Outlook handles file attachment links.

Overview

5.5

CVSS MEDIUM

Important

MS Severity

Not Exploited

MS Exploit Status

Less Likely

MS Exploit Likelihood

Category Information Disclosure

Released Aug 11 2020

Last Updated Aug 11 2020

Publicly Disclosed No

CISA KEV Not Listed

Known Exploits None Known

EPSS Score 0.07296 — 0.9381 percentile

NVD CVSS 5.5 MEDIUM — differs from MSRC

CVSS Vector

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

ATTACK VECTOR

Local

ATTACK COMPLEXITY

Low

PRIVILEGES REQUIRED

None

USER INTERACTION

Required

SCOPE

Unchanged

EPSS Score

0.07296

probability of exploitation in the next 30 days

0.9381 percentile - updated 2026-08-14

View on FIRST.org

Affected Products

11 affected products

Product	KB Article	Severity	Impact	Restart Required
Microsoft 365 Apps for Enterprise for 32-bit Systems	`Click to Run (Security Update)`	Important	Information Disclosure	No
Microsoft 365 Apps for Enterprise for 64-bit Systems	`Click to Run (Security Update)`	Important	Information Disclosure	No
Microsoft Office 2019 for 32-bit editions	`Click to Run (Security Update)`	Important	Information Disclosure	No
Microsoft Office 2019 for 64-bit editions	`Click to Run (Security Update)`	Important	Information Disclosure	No
Microsoft Outlook 2010 Service Pack 2 (32-bit editions)	`4484497 (Security Update)`	Important	Information Disclosure	Maybe
Microsoft Outlook 2010 Service Pack 2 (64-bit editions)	`4484497 (Security Update)`	Important	Information Disclosure	Maybe
Microsoft Outlook 2013 RT Service Pack 1	`4484486 (Security Update)`	Important	Information Disclosure	Maybe
Microsoft Outlook 2013 Service Pack 1 (32-bit editions)	`4484486 (Security Update)`	Important	Information Disclosure	Maybe
Microsoft Outlook 2013 Service Pack 1 (64-bit editions)	`4484486 (Security Update)`	Important	Information Disclosure	Maybe
Microsoft Outlook 2016 (32-bit edition)	`4484475 (Security Update)`	Important	Information Disclosure	Maybe
Microsoft Outlook 2016 (64-bit edition)	`4484475 (Security Update)`	Important	Information Disclosure	Maybe

Patches

4 patches

Article	Type	Restart
`Click to Run`	Security Update	No
`4484497`	Security Update	Maybe
`4484486`	Security Update	Maybe
`4484475`	Security Update	Maybe

Exploits & PoC

1 public PoC

Unverified third-party code

Public proof-of-concept repositories aggregated from PoC-in-GitHub. They are not reviewed and may be incomplete, non-functional, or malicious — inspect the code before running anything.

Repository	Stars	Published	Description
0neb1n/CVE-2020-1493	25	2020-08-25

Detection Rules

No public Sigma or Nuclei detection rule has been mapped to this CVE yet. Coverage is concentrated on exploited / high-profile vulnerabilities; check SigmaHQ for updates.

Acknowledgments

0neb1n working with Trend Micro's Zero Day Initiative

References

MSRC Advisory MITRE NVD