What is CVE-2021-22909?

CVE-2021-22909 is a high-severity vulnerability in Ui Edgemax Edgerouter, classified under Channel Accessible by Non-Endpoint. CVSS score: 7.5/10. Published 2021-05-27.

How severe is CVE-2021-22909?

High severity. CVSS v3 base score is 7.5 out of 10.

Is CVE-2021-22909 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Vulnerability in Ui Edgemax Edgerouter

CVE-2021-22909

A vulnerability found in EdgeMAX EdgeRouter V2.0.9 and earlier could allow a malicious actor to execute a man-in-the-middle (MitM) attack during a firmware update. This vulnerability is fixed in EdgeMAX EdgeRouter V2.0.9-hotfix.1 and later.

Published 2021-05-27 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.013 (69.8th percentile), scored 2026-10-19.

Low probability of exploitation in the next 30 days, but still tracked. 70th percentile — 69.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.013 · newest: 0.013 · change: 0.000

Affected products

Ui Edgemax Edgerouter
Ui Edgemax Edgerouter Firmware
Edgemax Edgerouter — versions Fixed Version: 2.0.9-hotfix.1 or later.

Weakness classification (CWE)

Public proof-of-concept exploits

redeltaglio/ubiquiti-configurator

References

community.ui.com/releases/Security-Advisory-Bulletin-018-018/cfa1566b-4bf8-427b… (Vendor Advisory)

Frequently asked questions

What is CVE-2021-22909?: CVE-2021-22909 is a high-severity vulnerability in Ui Edgemax Edgerouter, classified under Channel Accessible by Non-Endpoint. CVSS score: 7.5/10. Published 2021-05-27.
How severe is CVE-2021-22909?: High severity. CVSS v3 base score is 7.5 out of 10.
Is CVE-2021-22909 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.