CVE-2021-38690: Stack Overflow Vulnerability in QVR Elite, QVR Pro and QVR Guard

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2022-01-14 · updated 2026-06-17
Weakness: CWE-120

Description

A stack buffer overflow vulnerability has been reported to affect QNAP device running QVR Elite, QVR Pro, QVR Guard. If exploited, this vulnerability allows attackers to execute arbitrary code. We have already fixed this vulnerability in the following versions of QVR Elite, QVR Pro, QVR Guard: QuTS hero h5.0.0: QVR Elite 2.1.4.0 (2021/12/06) and later QuTS hero h4.5.4: QVR Elite 2.1.4.0 (2021/12/06) and later QTS 5.0.0: QVR Elite 2.1.4.0 (2021/12/06) and later QTS 4.5.4: QVR Elite 2.1.4.0 (2021/12/06) and later QTS 4.5.4: QVR Pro 2.1.3.0 (2021/12/06) and later QTS 5.0.0: QVR Pro 2.1.3.0 (2021/12/06) and later QTS 4.5.4: QVR Guard 2.1.3.0 (2021/12/06) and later QTS 5.0.0: QVR Guard 2.1.3.0 (2021/12/06) and later

Affected products

QNAP Systems Inc. QVR Elite: before 2.1.4.0 — fixed in 2.1.4.0
QNAP Systems Inc. QVR Guard: before 2.1.3.0 — fixed in 2.1.3.0
QNAP Systems Inc. QVR Pro: before 2.1.3.0 — fixed in 2.1.3.0

How to fix

Upgrade to a fixed version: QNAP Systems Inc. QVR Elite 2.1.4.0; QNAP Systems Inc. QVR Guard 2.1.3.0; QNAP Systems Inc. QVR Pro 2.1.3.0. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2021-38690 or the next vulnerability affects your stack