CVE-2021-47891

Name: CVE-2021-47891
Creator: NVD / NIST
Published: 2026-01-23T17:15:52.523+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.3/10EPSS 0.80%

Last modified Jun 17, 2026

CVE-2021-47891 is a critical-severity vulnerability rated 9.3/10 on the CVSS scale. Unified Remote 3.9.0.2463 contains a remote code execution vulnerability that allows attackers to send crafted network packets to execute arbitrary commands. Attackers can exploit the service by connecting to port 9512 and sending specially crafted packets to open a command prompt and download and execute malicious payloads.. EPSS estimates a 0.80% chance of exploitation in the next 30 days.

Description

Unified Remote 3.9.0.2463 contains a remote code execution vulnerability that allows attackers to send crafted network packets to execute arbitrary commands. Attackers can exploit the service by connecting to port 9512 and sending specially crafted packets to open a command prompt and download and execute malicious payloads.

Metrics

CVSS 3.1

9.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS 4.0

9.3/10

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS Probability

0.80%

51.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-306

References

Timeline

Published: Jan 23, 2026
Last Modified: Jun 17, 2026
Status: Deferred

Frequently Asked Questions

What is CVE-2021-47891?

How severe is CVE-2021-47891?

CVE-2021-47891 has a CVSS score of 9.3/10 (CRITICAL severity). The EPSS model estimates a 0.80% probability of exploitation in the next 30 days.

How do I fix CVE-2021-47891?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-47891?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST