CVE-2021-26427

Microsoft Exchange Server Remote Code Execution Vulnerability

Critical · published October 13, 2021

CVSS v3.1
9.0
EPSS
1%
Percentile
59.1
In the wild
Unconfirmed
What it is

🚨 A simple trick could turn your Microsoft Exchange Server into an attacker's playground! Just one malicious request is all it takes to unleash chaos. 🔥 Think of it like a hotel with a master key that opens all rooms without checking in — a sneaky intruder could waltz right in and access sensitive data with zero effort! An attacker could exploit this vulnerability to execute arbitrary code on your Exchange Server, potentially leading to data theft, unauthorized access, and complete system compromise. The consequences could be absolutely devastating, with disruption to business operations and loss of sensitive information.

Put simply

Think of it like a hotel with a master key that opens all rooms without checking in — a sneaky intruder could waltz right in and access sensitive data with zero effort! This remote code execution vulnerability in Microsoft Exchange Server allows attackers to execute arbitrary code by sending specially crafted requests. The flaw exists due to improper handling of certain requests, which can be manipulated by an attacker to gain control of the server.

What to do

An attacker could exploit this vulnerability to execute arbitrary code on your Exchange Server, potentially leading to data theft, unauthorized access, and complete system compromise. The consequences could be absolutely devastating, with disruption to business operations and loss of sensitive information. Patch your Microsoft Exchange Server immediately to the latest version. It's essential to apply all security updates and regularly check for any vulnerabilities to keep your systems safe. Also, consider implementing strict input validation and monitoring for suspicious activity. You've got this! Follow these steps, and you’ll be back to hero status in no time! 🛡️

The record
Technical detail
CVSS v3.1
9.0 · CRITICAL
Vector
CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C
CVSS v4.0
Not supplied
EPSS
0.00893 · 59.1th percentile
Published
2021-10-13T00:26Z
EPSS history
Timeline
  • 13 OCT 00:26Z
    Microsoft Exchange Server Remote Code Execution Vulnerability
    cvelistv5