Critical EPSS 0.19982 2020-01 archive

Executive Summary

A remote code execution vulnerability exists in ASP.NET Core software when the software fails to handle client deleted connections. An attacker who successfully exploited the vulnerability could run arbitrary code in memory on the server. Exploitation of the vulnerability requires that a user perform certain actions during the connection process. The security update addresses the vulnerability by correcting how ASP.NET Core handles deleted connections.

Overview

Critical
MS Severity
Not Exploited
MS Exploit Status
Less Likely
MS Exploit Likelihood
Category Remote Code Execution
Released Jan 14 2020
Last Updated Jan 14 2020
Publicly Disclosed No
CISA KEV Not Listed
Known Exploits None Known
EPSS Score 0.19982 — 0.97101 percentile

EPSS Score

0.19982
probability of exploitation in the next 30 days
0.97101 percentile - updated 2026-06-20
View on FIRST.org

Affected Products

3 affected products
Product KB Article Severity Impact Restart Required
ASP.NET Core 2.1 Release Notes (Security Update) Critical Remote Code Execution Maybe
ASP.NET Core 3.0 Release Notes (Security Update) Critical Remote Code Execution Maybe
ASP.NET Core 3.1 Release Notes (Security Update) Critical Remote Code Execution Maybe

Patches

1 patch
Article Type Restart
Release Notes Security Update Maybe

Known Exploits

Acknowledgments

Brennan Conroy of Microsoft Corporation