CVE-2020-0878

Microsoft Browser Memory Corruption Vulnerability

  • Medium 4.2
  • Exploited: added to CISA KEV 3 Nov 2021
  • Used in ransomware campaigns

Description

<p>A remote code execution vulnerability exists in the way that Microsoft browsers access objects in memory. The vulnerability could corrupt memory in a way that could allow an attacker to execute arbitrary code in the context of the current user. An attacker who successfully exploited the vulnerability could gain the same user rights as the current user. If the current user is logged on with administrative user rights, the attacker could take control of an affected system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights.</p> <p>An attacker could host a specially crafted website that is designed to exploit the vulnerability through Microsoft browsers, and then convince a user to view the website. The attacker could also take advantage of compromised websites, or websites that accept or host user-provided content or advertisements, by adding specially crafted content that could exploit the vulnerability. In all cases, however, an attacker would have no way to force users to view the attacker-controlled content. Instead, an attacker would have to convince users to take action, typically via an enticement in email or instant message, or by getting them to open an email attachment.</p> <p>The security update addresses the vulnerability by modifying how Microsoft browsers handle objects in memory.</p>

Key facts

Published
11 Sep 2020
Last changed
21 Oct 2025
Assigned by
microsoft
KEV added
3 Nov 2021
KEV fix due
3 May 2022
Used in ransomware
Yes, according to CISA
EPSS
2.696% likely to be exploited in the next 30 days, higher than 86.154% of CVEs (scores for 15 Nov 2026)
SSVC (CISA)
Exploitation: active; Automatable: no; Technical impact: total

Severity scores

Each score is shown as its source gave it. They are not averaged or merged.

  • 4.2CVSS 3.1, Mediumfrom the CNA (microsoft)CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N/E:P/RL:O/RC:C

What to do

  • Apply updates per vendor instructions.CISA KEV required action

Historical context and remediation

This reference retains the original CVE publication date. A recent record update does not mean a new attack occurred.

No separately sourced impact summary is available on this page yet. Consult the description, version data and dated exploitation evidence.

Version statuses below come from the CNA. An “unaffected” version is not necessarily a currently supported release or proof of a patch date. EPSS is a dated risk estimate, not a count of historical attacks.

Read the original CVE record.

Affected products

VendorProductVersions
MicrosoftChakraCore
  • 0 up to but excluding publication (affected)
MicrosoftMicrosoft Edge (EdgeHTML-based)
  • 1.0..0 up to but excluding publication (affected)
MicrosoftInternet Explorer 9
  • 1.0.0 up to but excluding publication (affected)
MicrosoftInternet Explorer 11
  • 1.0.0 up to but excluding publication (affected)

Timeline

  1. 11 Sep 2020 Published
  2. 3 Nov 2021 CVE-2020-0878 added to CISA KEV
  3. 3 Nov 2021 Added to the CISA KEV catalogue

Weakness

References