Actively exploited · Published Sep 11, 2020 · Assigned by microsoft

CVE-2020-0878Microsoft Browser Memory Corruption Vulnerability

Medium 4.2 Exploited Ransomware

In plain English

A medium-severity out-of-bounds write in ChakraCore from Microsoft. Attackers are actively exploiting it in the wild (listed by CISA on November 3, 2021). It has been used in ransomware campaigns. The chance it is exploited in the next 30 days is estimated at 2.7% (higher than 86% of all known vulnerabilities). Apply updates per vendor instructions.

Severity (CVSS 3.1)4.2Medium
Exploit odds (30 days)2.7%top 14.0% of all CVEs
Exploited in the wildYesCISA KEV since Nov 3, 2021
Attack toolingNoneno public tooling known

CISA guidance

Apply updates per vendor instructions.

Federal agencies must remediate by May 3, 2022.

Official 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>

Affected products (as reported)

VendorProductVersions
Microsoft ChakraCore 0 – before publication
Microsoft Microsoft Edge (EdgeHTML-based) 1.0..0 – before publication
Microsoft Internet Explorer 9 1.0.0 – before publication
Microsoft Internet Explorer 11 1.0.0 – before publication

Weakness: CWE-787 · Vector: 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

References