CVE-2021-27104

Name: CVE-2021-27104
Creator: NVD / NIST
Published: 2021-02-16T21:15:13.28+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10Actively ExploitedEPSS 56.69%

Last modified Jun 17, 2026

CVE-2021-27104 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. Accellion FTA 9_12_370 and earlier is affected by OS command execution via a crafted POST request to various admin endpoints. The fixed version is FTA_9_12_380 and later.. CISA has confirmed active exploitation in the wild. EPSS estimates a 56.69% chance of exploitation in the next 30 days.

Description

Accellion FTA 9_12_370 and earlier is affected by OS command execution via a crafted POST request to various admin endpoints. The fixed version is FTA_9_12_380 and later.

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

EPSS Probability

56.69%

98.9th percentile

Probability of exploitation in the next 30 days. Learn more

Exploitation Status

This vulnerability is listed in CISA’s Known Exploited Vulnerabilities catalog, confirming active exploitation in the wild. Federal agencies must remediate by Nov 17, 2021.

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Accellion	Fta	<= 9_12_370

References

https://github.com/accellion/CVEs/blob/main/CVE-2021-27104.txtBroken Link, Third Party Advisory
https://www.accellion.com/products/fta/Product, Vendor Advisory
https://github.com/accellion/CVEs/blob/main/CVE-2021-27104.txtBroken Link, Third Party Advisory
https://www.accellion.com/products/fta/Product, Vendor Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-27104US Government Resource

Timeline

Published: Feb 16, 2021
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2021-27104?

Accellion FTA 9_12_370 and earlier is affected by OS command execution via a crafted POST request to various admin endpoints. The fixed version is FTA_9_12_380 and later.

How severe is CVE-2021-27104?

CVE-2021-27104 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 56.69% probability of exploitation in the next 30 days. This vulnerability is listed in CISA's Known Exploited Vulnerabilities catalog.

How do I fix CVE-2021-27104?

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-2021-27104?

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

Scan your code now

Source: NVD / NIST