How severe is CVE-2020-2509?

CVE-2020-2509 has a CVSS score of 9.8/10, rated CRITICAL. Immediate patching is strongly recommended.

Which packages are affected by CVE-2020-2509?

Affected package information for CVE-2020-2509 is not yet fully mapped. Check the official advisory links for details.

How do I fix CVE-2020-2509?

No fixed version has been published for CVE-2020-2509 yet. Monitor the advisory for updates, apply mitigations recommended by the vendor, and use O3 Security to track when a fix becomes available in your stack.

Is CVE-2020-2509 actively exploited in the wild?

Yes. There are 5 known exploit references for CVE-2020-2509, including 4 in-the-wild exploitations observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2020-2509?

CVE-2020-2509 has an EPSS (Exploit Prediction Scoring System) score of 84.0%, placing it in the 99th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. A score above 50% indicates significantly elevated exploitation risk — immediate patching is strongly recommended.

Is CVE-2020-2509 in the CISA Known Exploited Vulnerabilities catalog?

Yes. CVE-2020-2509 (QNAP Network-Attached Storage (NAS) Command Injection Vulnerability) was added to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2022-04-11. CISA required all US federal civilian agencies to remediate this vulnerability by 2022-05-02. The required action was: Apply updates per vendor instructions. Being listed in the KEV catalog is the strongest possible confirmation of active exploitation — treat this as a critical priority.

What type of vulnerability is CVE-2020-2509?

CVE-2020-2509 is classified as CWE-77 (CWE-77), OS Command Injection (CWE-78). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

Which products and versions are affected by CVE-2020-2509?

CVE-2020-2509 affects qnap qts (66 versions, e.g. 4.2.6, 4.3.3.0174, 4.3.3.0868…); qnap quts hero (2 versions, e.g. h4.5.1, h4.5.1.1472). Check the affected-products list on this page against your deployed version to confirm exposure.

When was CVE-2020-2509 published, and has it been updated?

CVE-2020-2509 was published on April 17, 2021 and was last updated on October 27, 2025. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CISA KEV·Added 2022-04-11 — agencies required to remediate by 2022-05-02

CVE-2020-2509

CRITICAL

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.…

Published

Apr 17, 2021

Updated

Oct 27, 2025

Affected

0 pkgs

Patched

None yet

Exploits

5 known

EPSS Exploitation Probability

via FIRST.org ↗

84.0%probability of exploitation in next 30 days

Very High Risk99th percentile0.00%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Description

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

Affected Products

2 products · 86 configurations

qtsqnap

≥ 4.4.0 && < 4.5.1

66 versions

4.2.64.3.3.01744.3.3.08684.3.3.09984.3.3.10514.3.3.10984.3.3.11614.3.3.12524.3.3.13154.3.3.13864.3.3.14324.3.4.0358

quts heroqnap

< h4.5.1

2 versions

h4.5.1h4.5.1.1472

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

A command injection vulnerability has been reported to affect QTS and Qu…

cisa.govAPIApr 2022

A command injection vulnerability has been reported to affect QTS and Qu…

cisa.govCISAApr 2022

A command injection vulnerability has been reported to affect QTS and Qu…

github.comGithubJul 2022

A command injection vulnerability has been reported to affect QTS and Qu…

techzine.euAPIApr 2021

Frequently Asked Questions

O3 Security · Impact-Aware SCA

Is CVE-2020-2509 in your stack?

O3 detects CVE-2020-2509 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

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