CVE-2025-66620CWE-553

Columbia Weather Systems MicroServer Command Shell in Externally Accessible Directory

High · published January 7, 2026

CVSS v4.0
8.6
EPSS
0%
Percentile
37.9
In the wild
Unconfirmed
What it is

⚡ An unused webshell in MicroServer is a ticking time bomb for admins! This vulnerability allows unlimited login attempts, making it alarmingly easy for attackers to slip in undetected. 🔥 Think of it like a hotel with a staff door that never gets locked; anyone with a key can waltz in, and once inside, they can rummage through sensitive guest information or even change the locks permanently. 🏨 If an attacker gains admin access, they could establish reverse shells for continuous access, modify or delete critical data, or even turn the server into a puppet for their malicious plans. The worst part? It's like handing over the keys to your entire operation without a second thought!

Put simply

Think of it like a hotel with a staff door that never gets locked; anyone with a key can waltz in, and once inside, they can rummage through sensitive guest information or even change the locks permanently. 🏨 CVE-2025-66620 allows attackers to exploit an unused webshell in MicroServer, enabling unlimited login attempts with sudo rights on specific files and directories. This opens the door for limited shell access, allowing data manipulation and persistence.

What to do

If an attacker gains admin access, they could establish reverse shells for continuous access, modify or delete critical data, or even turn the server into a puppet for their malicious plans. The worst part? It's like handing over the keys to your entire operation without a second thought! Immediately review user access to MicroServer and restrict administrative privileges to necessary personnel only. Implement a strong password policy and consider introducing account lockout thresholds to mitigate brute force attacks. Finally, patch MicroServer to the latest version as soon as it’s released! You've got this! Follow these steps, and you'll keep your server safe and sound. 🛡️

The record
Technical detail
CVSS v4.0
8.6 · HIGH
Vector
CVSS:4.0/AV:A/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
EPSS
0.00454 · 37.9th percentile
Weakness
CWE-553 · Command Shell in Externally Accessible Directory
Published
2026-01-07T20:08Z
EPSS history
Timeline
  • 07 JAN 20:08Z
    Columbia Weather Systems MicroServer Command Shell in Externally Accessible Directory
    cvelistv5