Cyber Resilience

CVE-2021-4406

CriticalRCE

Published: 10 July 2023

Published
10 July 2023
Modified
24 September 2025
KEV Added
Patch
CVSS Score v3.1 9.1 CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
EPSS Score 0.0017 38.7th percentile
Risk Priority 18 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-4406 is a critical-severity Command Injection (CWE-77) vulnerability in Osnexus Quantastor. Its CVSS base score is 9.1 (Critical).

Operationally, ranked at the 38.7th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

An authenticated attacker is able to create alerts that trigger a stored XSS attack. POC * go to the alert manager * open the ITSM tab * add a webhook with the URL/service token value ' -h && id |…

more

tee /tmp/ttttttddddssss #' (whitespaces are tab characters) * click add * click apply * create a test alert * The test alert will run the command “id | tee /tmp/ttttttddddssss” as root. * after the test alert inspect /tmp/ttttttddddssss it'll contain the ids of the root user.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

osnexus
quantastor
≤ 6.0.0.355

Mitigating Controls

No mitigating controls mapped yet. The per-CVE control annotator has not reached this CVE.

References