What is CVE-2021-40870?

CVE-2021-40870 is a critical-severity vulnerability in Aviatrix Controller, classified under Relative Path Traversal. CVSS score: 9.8/10. Published 2021-09-13.

How severe is CVE-2021-40870?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Is CVE-2021-40870 known to be exploited?

Yes. CVE-2021-40870 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2022-01-18), indicating it is being actively exploited. 18 public proof-of-concept repositories are indexed.

Path Traversal in Aviatrix Controller

CVE-2021-40870

An issue was discovered in Aviatrix Controller 6.x before 6.5-1804.1922. Unrestricted upload of a file with a dangerous type is possible, which allows an unauthenticated user to execute arbitrary code via directory traversal.

Published 2021-09-13 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.930 (99.8th percentile), scored 2026-10-16.

High probability of exploitation in the next 30 days — patch promptly. 100th percentile — 99.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.930 · newest: 0.930 · change: 0.000

Affected products

Aviatrix Controller

Weakness classification (CWE)

CWE-23 — Relative Path Traversal

CISA KEV (Known Exploited Vulnerabilities)

This CVE is on the CISA KEV catalog, added on 2022-01-18. CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.

BOD 22-01 due date: 2022-02-01.

Required action: Apply updates per vendor instructions.

Public proof-of-concept exploits

References

docs.aviatrix.com/HowTos/UCC_Release_Notes.html (Release Notes, Vendor Advisory)
wearetradecraft.com/advisories/tc-2021-0002/ (Exploit, Third Party Advisory)
packetstormsecurity.com/files/164461/Aviatrix-Controller-6.x-Path-Traversal-Cod… (Exploit, VDB Entry, Third Party Advisory)
134c704f-9b21-4f2e-91b3-4a467353bcc0 (US Government Resource)

Frequently asked questions

What is CVE-2021-40870?: CVE-2021-40870 is a critical-severity vulnerability in Aviatrix Controller, classified under Relative Path Traversal. CVSS score: 9.8/10. Published 2021-09-13.
How severe is CVE-2021-40870?: Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2021-40870 known to be exploited?: Yes. CVE-2021-40870 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2022-01-18), indicating it is being actively exploited. 18 public proof-of-concept repositories are indexed.