CISA KEV Critical Injection

CVE-2020-2509 — QNAP Network-Attached Storage (NAS) Command Injection Vulnerability

A command injection vulnerability has been reported to affect QTS and QuTS hero. If exploited, this vulnerability allows attackers to execute arbitrary commands in a compromised application. We have already fixed this vulnerability in the following versions: QTS 4.5.2.1566 Build 20210202 and later QTS 4.5.1.1495 Build 20201123 and later QTS 4.3.6.1620 Build 20210322 and later QTS 4.3.4.1632 Build 20210324 and later QTS 4.3.3.1624 Build 20210416 and later QTS 4.2.6 Build 20210327 and later QuTS hero h4.5.1.1491 build 20201119 and later

Published Apr 17, 2021 · Updated Oct 13, 2026 · Sources: CISA Known Exploited Vulnerabilities, NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP, GitHub Security Advisories · CNA: qnap

High

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

CISA KEV · Apr 11, 2022 Proofs of concept on GitHub · 1

How the score was calculated

Confirmed exploitation (CISA KEV)+35
Public exploit/PoC (github)+6
EPSS 34% (30-day exploitation probability)+15
Technical severity (critical)+10
Automatable exploitation (SSVC)+3

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Confirmed

CISA KEV, listed Apr 11, 2022

EPSS FIRST

33.99%

ahead of 98% of scored CVEs · Oct 14, 2026

Affects

Qnap

Qts and 3 more

CVSS base

9.8

Critical · 4 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation

Active

none · proof-of-concept · active

Automatable

Yes

can an attacker script the kill-chain steps

Technical impact

Total

partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

CISA required action CISA

Apply updates per vendor instructions.

US federal deadline: May 2, 2022 — passed 1627 day(s) ago

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Qnap Qts, Qnap Quts Hero, QNAP Systems Inc. QTS…).
Treat as emergency remediation: the CVE is in CISA KEV (confirmed exploitation).
The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
No fix documented in the sources: reduce exposure and monitor the vendor advisory.
EPSS ahead of 98% of scored CVEs: prioritize it in the patch queue.
Search available logs for exploit probes matching the vulnerability class (injection), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Qnap	Qts	version 4.3.4.0593version 4.3.4.1463version 4.3.4.1417version 4.3.4.1368version 4.3.4.1282version 4.3.4.1190version 4.3.4.1082version 4.3.4.1029 and 75 more version 4.3.4.0899version 4.3.4.0604version 4.3.4.0597version 4.3.6version 4.3.4.0569version 4.3.4.0561version 4.3.4.0557version 4.3.4.0551version 4.3.4.0526version 4.3.4.0516version 4.3.4.0506version 4.3.4.0486version 4.3.4.0483version 4.3.4.0451version 4.3.6.1154version 4.5.1.1465version 4.5.1.1461version 4.5.1.1456version 4.5.1version 4.3.6.1446version 4.3.6.1411version 4.3.6.1333version 4.3.6.1286version 4.3.6.1263version 4.3.6.1218version 4.3.4.0435version 4.3.6.1070version 4.3.6.1033version 4.3.6.1013version 4.3.6.0993version 4.3.6.0979version 4.3.6.0959version 4.3.6.0944version 4.3.6.0923version 4.3.6.0907version 4.3.6.0895version 4.2.6-build_20190921version 4.3.3.1051version 4.3.3.0998version 4.3.3.0868version 4.3.3.0174version 4.2.6-build_20200821version 4.2.6-build_20200611version 4.2.6-build_20200421version 4.2.6-build_20200109version 4.2.6-build_20191107version 4.3.4.0434version 4.2.6-build_20190730version 4.2.6-build_20190322version 4.2.6-build_20170517version 4.2.6≥ 4.4.0 and < 4.5.1≥ 4.3.5 and < 4.3.6< 4.2.6version 4.5.1.1480version 4.5.2version 4.3.3.1161version 4.3.4.0427version 4.3.4.0416version 4.3.4.0411version 4.3.4.0387-beta2version 4.3.4.0387version 4.3.4.0374-beta1version 4.3.4.0374version 4.3.4.0372-beta1version 4.3.4.0372version 4.3.4.0370-beta1version 4.3.4.0370version 4.3.4.0358-beta1version 4.3.4.0358version 4.3.3.1432version 4.3.3.1386version 4.3.3.1315version 4.3.3.1252version 4.3.3.1098	Vulnerable	NIST National Vulnerability Database
Qnap	Quts Hero	< h4.5.1version h4.5.1version h4.5.1.1472	Vulnerable	NIST National Vulnerability Database
QNAP Systems Inc.	QTS	< 4.5.1.1495 Build 20201123< 4.2.6 Build 20210327< 4.3.3.1624 Build 20210416< 4.3.4.1632 Build 20210324< 4.3.6.1620 Build 20210322< 4.5.2.1566 Build 20210202	Vulnerable	CVE Program (cve.org) e CISA ADP
QNAP Systems Inc.	QuTS hero	< h4.5.1.1491 build 20201119	Vulnerable	CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Network

Attack complexity

Low

Privileges required

None

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Scored by
9.8	CVSS 3.1	Critical	3.9	5.9	nvd@nist.gov via NIST National Vulnerability Database
9.8	CVSS 3.1	Critical	3.9	5.9	134c704f-9b21-4f2e-91b3-4a467353bcc0 via NIST National Vulnerability Database
9.8	CVSS 3.1	Critical	—	—	GitHub, Inc. via GitHub Security Advisories
9.8	CVSS 3.1	Critical	—	—	CISA-ADP via CVE Program (cve.org) e CISA ADP
7.5	CVSS 2.0	High	10.0	6.4	nvd@nist.gov via NIST National Vulnerability Database

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H (score shown at the top: nvd@nist.gov)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-77 · Command Injection

Other CVEs with this weakness →

CISA KEV details CISA

CISA lists a CVE once it has evidence of exploitation against real targets.

Listed

Apr 11, 2022

Federal deadline

May 2, 2022

passed 1627 day(s) ago

Ransomware use

Unknown

CISA records ransomware use only for campaigns it has confirmed, so “Unknown” means unrecorded, not ruled out. The deadline binds US federal agencies; for everyone else it is a reference date.

Public exploits, PoCs and detection templates

Public code that demonstrates or tests the flaw raises the odds of mass exploitation — and Nuclei templates help find vulnerable assets in your environment.

Proofs of concept on GitHub

QNAP N-Day (Probably not CVE-2020-2509) ★ 14 Jul 27, 2022

Warning: public PoCs are sometimes disguised malware. Use them only for authorized testing in an isolated environment. This portal does not host exploit code — it only points to the sources.

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 33.99%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
Look for parameters with command/query metacharacters and unexpected child processes of the service.
Hunt retroactively in logs from before Apr 11, 2022 (KEV listing): exploitation may have started earlier.

web/proxy/WAF logsnetwork IDS/IPSapplication logsendpoint telemetry (EDR)

Timeline

What happened to this CVE, newest first.

2026
Affected products added · qnap systems inc./qts, qnap systems inc./quts hero
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
SSVC assessment updated
Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 13, 2026
Affected products added · qnap/qts, qnap/quts hero
Oct 13, 2026 · NIST National Vulnerability Database
CVSS changed · 9.8
Oct 13, 2026 · NIST National Vulnerability Database
Source status changed · → Analyzed
Oct 13, 2026 · NIST National Vulnerability Database
Added to CISA KEV (detected)
Oct 13, 2026 · CISA Known Exploited Vulnerabilities
Record created in this database
Oct 13, 2026 · CISA Known Exploited Vulnerabilities
2022
Added to CISA KEV catalog
Apr 10, 2022 · CISA
2021
CVE published
Apr 17, 2021 · qnap

Source activity

Repeated readings are counted rather than listed.

2× References added · Oct 13, 2026 – Oct 13, 2026
1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

4 on the record

www.qnap.com/en/security-advisory/qsa-21-05
Vendor Advisory, x_refsource_MISC, NIST National Vulnerability Database
www.cisa.gov/known-exploited-vulnerabilities-catalog
US Government Resource, NIST National Vulnerability Database
github.com/advisories/GHSA-77jf-5mcg-g6m9
GitHub Security Advisories
nvd.nist.gov/vuln/detail/CVE-2020-2509
GitHub Security Advisories

Elsewhere on this site

Qnap
every CVE for this vendor

2022-04
what else CISA listed that month

Injection
same class

CWE-77
other pages naming this weakness

Related CVEs (same products)

High CVE-2026-24719 QTS, QuTS hero Jun 10, 2026
High CVE-2026-24716 QTS, QuTS hero Jun 10, 2026
Medium CVE-2026-24717 QTS, QuTS hero Jun 10, 2026
High CVE-2025-66281 QTS, QuTS hero Jun 10, 2026
High CVE-2026-22893 QTS, QuTS hero Jun 10, 2026
High CVE-2025-66279 QTS, QuTS hero Jun 10, 2026

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No fixed version, patch or mitigation documented.
No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2020-2509 is "QNAP Network-Attached Storage (NAS) Command Injection Vulnerability", rated Critical. It affects Qts (Qnap); versions are in the scope table. It is in CISA KEV: there is evidence of real-world exploitation. CVSS 9.8 describes technical severity. EPSS 33.99% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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