CVE-2021-26877

CVE-2021-26877

Critical · published March 11, 2021

CVSS v3.1
9.8
EPSS
18%
Percentile
97.2
In the wild
Unconfirmed
What it is

🚨 This Windows DNS Server vulnerability allows attackers to execute remote code with a single malicious request, turning your server into a rogue agent! 🔥 Think of it as a trusted delivery service that not only accepts packages but also opens and executes any instructions inside, regardless of their origin—an absolute recipe for disaster! If exploited, an attacker could run any code they wish on your DNS server, leading to total control over your network. This means they could manipulate traffic, steal sensitive data, or even stage further attacks—absolutely devastating scenarios!

Put simply

Think of it as a trusted delivery service that not only accepts packages but also opens and executes any instructions inside, regardless of their origin—an absolute recipe for disaster! The vulnerability arises from improper handling of DNS requests, allowing for remote code execution without authentication. An attacker can send specially crafted packets that the server unwittingly processes, executing their code as if it were legitimate.

What to do

If exploited, an attacker could run any code they wish on your DNS server, leading to total control over your network. This means they could manipulate traffic, steal sensitive data, or even stage further attacks—absolutely devastating scenarios! Immediately patch your Windows DNS Server to the latest available version to close this loophole. Also, review your network configurations and monitor for any unusual DNS traffic. Keeping your systems updated is crucial! You've got this! With the right steps, you'll secure your server in no time! 🛡️

The record
Technical detail
CVSS v3.1
9.8 · CRITICAL
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.17740 · 97.2th percentile
Published
2021-03-11T21:15Z
Affected products (9)
ProductVersionsFixed in
microsoft/windows_server_2008all versions—
microsoft/windows_server_2008all versions—
microsoft/windows_server_2012all versions—
microsoft/windows_server_2012all versions—
microsoft/windows_server_2016all versions—
microsoft/windows_server_2016all versions—
microsoft/windows_server_2016all versions—
microsoft/windows_server_2016all versions—
microsoft/windows_server_2019all versions—
References (2)
EPSS history
Timeline
  • 11 MAR 15:40Z
    Windows DNS Server Remote Code Execution Vulnerability
    cvelistv5