CVE-2023-47565 | Legacy VioStor NVR

Exp

An OS command injection vulnerability has been found to affect legacy QNAP VioStor NVR models running QVR Firmware 4.x. If exploited, the vulnerability could allow authenticated users to execute commands via a network. We have already fixed the vulnerability in the following versions: QVR Firmware 5.0.0 and later

Published: 2023-12-08 Last update: 2026-02-26 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2023-47565 is rated Critical Active Threat (90.5/100): CVSS High severity, with high exploitation likelihood (EPSS 86.75%, 99th percentile). Core evidence: CISA KEV confirms active exploitation (added 2023-12-21) affecting QNAP / VioStor NVR. a weakness (CWE-78) Unauthenticated remote administrative access may be possible. Mandatory action: The CISA remediation deadline has passed—treat as an emergency patch priority.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

CISA KEV Record for CVE-2023-47565

Name: QNAP VioStor NVR OS Command Injection Vulnerability · CISA KEV detail

Exploit added: 2023-12-21

Action due: 2024-01-11

Required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

Exploit prediction scoring system (EPSS) score for CVE-2023-47565

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-04-08 88.08% 86.75% -1.33%
2 2026-04-02 85.89% 88.08% +2.19%
3 2026-03-08 85.89%

Full EPSS history (29 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-47565

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.0 3.1 HIGH
CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:A)
Attacker has to be nearby on the network—same office, same link, that vibe—not the whole wide internet.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
2.1 5.9 [email protected]
8.8 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
2.8 5.9 [email protected]

Weakness enumeration for CVE-2023-47565

Affected software / configurations for CVE-2023-47565

Vendor Product Version Raw CPE
qnap qvr_firmware >= 4.0.0, < 5.0.0 cpe:2.3:o:qnap:qvr_firmware:*:*:*:*:*:*:*:*

References for CVE-2023-47565

cvelogic Threat Intelligence