Microsoft Office
CVE-2020-16949 — Microsoft Outlook Denial of Service Vulnerability
Executive Summary
A denial of service vulnerability exists in Microsoft Outlook software when the software fails to properly handle objects in memory. An attacker who successfully exploited the vulnerability could cause a remote denial of service against a system. Exploitation of the vulnerability requires that a specially crafted email be sent to a vulnerable Outlook server. The security update addresses the vulnerability by correcting how Microsoft Outlook handles objects in memory.
Overview
4.7
CVSS MEDIUM
Moderate
MS Severity
Not Exploited
MS Exploit Status
Less Likely
MS Exploit Likelihood
CVSS Vector
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H/E:P/RL:O/RC:C
ATTACK VECTOR
Local
ATTACK COMPLEXITY
High
PRIVILEGES REQUIRED
Low
USER INTERACTION
None
SCOPE
Unchanged
CONFIDENTIALITY
None
INTEGRITY
None
AVAILABILITY
High
EXPLOIT CODE MATURITY
Proof-of-Concept
REMEDIATION LEVEL
Official Fix
REPORT CONFIDENCE
Confirmed
Temporal Score: 4.2
EPSS Score
0.02968
probability of exploitation in the next 30 days
0.86029 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) |
Moderate | Denial of Service | No |
| Microsoft 365 Apps for Enterprise for 64-bit Systems | Click to Run (Security Update) |
Moderate | Denial of Service | No |
| Microsoft Office 2019 for 32-bit editions | Click to Run (Security Update) |
Moderate | Denial of Service | No |
| Microsoft Office 2019 for 64-bit editions | Click to Run (Security Update) |
Moderate | Denial of Service | No |
| Microsoft Outlook 2010 Service Pack 2 (32-bit editions) | 4486663 (Security Update) |
Moderate | Denial of Service | Maybe |
| Microsoft Outlook 2010 Service Pack 2 (64-bit editions) | 4486663 (Security Update) |
Moderate | Denial of Service | Maybe |
| Microsoft Outlook 2013 RT Service Pack 1 | 4484524 (Security Update) |
Moderate | Denial of Service | Maybe |
| Microsoft Outlook 2013 Service Pack 1 (32-bit editions) | 4484524 (Security Update) |
Moderate | Denial of Service | Maybe |
| Microsoft Outlook 2013 Service Pack 1 (64-bit editions) | 4484524 (Security Update) |
Moderate | Denial of Service | Maybe |
| Microsoft Outlook 2016 (32-bit edition) | 4486671 (Security Update) |
Moderate | Denial of Service | Maybe |
| Microsoft Outlook 2016 (64-bit edition) | 4486671 (Security Update) |
Moderate | Denial of Service | Maybe |
Patches
4 patches
| Article | Type | Restart |
|---|---|---|
Click to Run |
Security Update | No |
4486663 |
Security Update | Maybe |
4484524 |
Security Update | Maybe |
4486671 |
Security Update | Maybe |
Exploits & PoC
No public exploit or PoC has been linked for this CVE yet. When available, references are sourced from public repositories and may be unverified or non-functional — review carefully before use.
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
References
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