CVE-2020-16949 Microsoft Outlook Denial of Service Vulnerability
An attacker can cause a remote denial of service in Microsoft Outlook by sending a specially crafted email that triggers improper memory handling.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2020-16949?
CVE-2020-16949 is a medium-severity denial of service vulnerability in Microsoft 365 Apps, published on 16 Oct 2020. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
<p>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.</p> <p>Exploitation of the vulnerability requires that a specially crafted email be sent to a vulnerable Outlook server.</p> <p>The security update addresses the vulnerability by correcting how Microsoft Outlook handles objects in memory.</p>
Weakness: CWE-401
Which versions are affected by CVE-2020-16949?
It affects 11 products.
Products include Microsoft 365 Apps, Microsoft Office, Microsoft Outlook, Microsoft Windows 10, Microsoft Windows 7, Microsoft Windows 8.1 and 5 more.
How do I fix CVE-2020-16949?
No fix has been published for CVE-2020-16949 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2020-16949 being exploited?
There is no known exploitation of CVE-2020-16949 in the wild and no public exploit code.
Other vulnerabilities in Microsoft 365 Apps
- CVE-2024-21413 Microsoft Outlook Improper Input Validation
- CVE-2023-23397 Microsoft Office Outlook Privilege Escalation
- CVE-2024-38189 Microsoft Project Remote Code Execution Vulnerability
- CVE-2023-35311 Microsoft Outlook Security Feature Bypass
- CVE-2026-21514 Microsoft Office Word Reliance on Untrusted Inputs in a Security Decision
Sources
Also known as GHSA-cvmr-qp3p-228w.