CVE-2020-2509
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
- CVSS
- 9.8Criticalscored by CISA
- Exploited in the wild
- Yes, in CISA KEV since 11 Apr 2022CISA deadline for US federal agencies: 2 May 2022unvetted proof-of-concept code on github
- EPSS
- 34.0%chance of exploitation in the next 30 daystop 2% of scored CVEsFIRST score of 11 Nov 2026
- Fix
- Patch availablesee the advisories in the references
- Published
- 17 Apr 2021analysed here 12 Nov 2026
Do first. Apply updates per vendor instructions. (CISA's required action for this KEV entry)
Summary
Triage
- Attack surface
- Server-side
- Exploitable
- At runtime
- Attack vector
- network
- Can a WAF block it?
- Partly. See why
The summary, impact and action text on this page are written by our AI analysis pipeline, or taken from the NVD description when a CVE was imported from NVD. They are not the vendor's wording: check them against the sources. A longer AI executive summary and technical analysis are generated for signed-in accounts on the Max plan.
Affected products
| Product | Affected versions | Vendor says fixed in |
|---|---|---|
| QNAP Systems Inc. QTS | < 4.5.2.1566 Build 20210202< 4.5.1.1495 Build 20201123< 4.3.6.1620 Build 20210322< 4.3.4.1632 Build 20210324< 4.3.3.1624 Build 20210416< 4.2.6 Build 20210327Vendor says fixed in: not stated | |
| QNAP Systems Inc. QuTS hero | < h4.5.1.1491 build 20201119Vendor says fixed in: not stated |
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.
Products named in our analysis
- qnap:qts
- qnap:quts_hero
Fix and mitigation
WAF and other mitigations
Can a WAF block it? Partly. Command injection puts shell syntax into the request. WAF rules catch common shell commands but miss encoded or unusual payloads.
Also consider: input validation · RASP · shlex/execve-style APIs
Based on the weakness type only; no CVE-specific evidence yet. We check Cloudflare, AWS, Google Cloud Armor and Azure; for Akamai, Imperva, Fastly, F5, ask your vendor.
Remediation steps (AI-written)
Step-by-step remediation is generated for accounts on the Max plan, for CVEs that match a technology in their stack. Add this technology to your stack to see the fix checklist.
Exploitation evidence
- CISA KEV catalog
- Listed since 11 Apr 2022.
- CISA due date
- 2 May 2022, the remediation deadline for US federal agencies
- CISA required action
- Apply updates per vendor instructions.
- Public exploit code
- Unvetted proof-of-concept code on GitHub: 1 GitHub proof of concept
- CISA SSVC
- exploitation active, automatable yes, technical impact totalAssessed by CISA 6 Feb 2025 (SSVC 2.0.3). Exploitation is none, poc (public proof of concept) or active.
GitHub proofs of concept
- jbaines-r7/overkill14 stars
Listed so you can judge urgency, not as a recommendation to run anything. GitHub “proofs of concept” are unvetted: some are fake or carry malware. Exploit-DB marks the entries its staff verified.
Timeline
- 17 Apr 2021Published
- 11 Apr 2022Added to CISA KEV (exploited in the wild)359 days (about 12 months) later
- 2 May 2022CISA remediation due date (US federal agencies)21 days later
- 27 Jul 2022First proof-of-concept repository on GitHub (unvetted)86 days (about 3 months) later
- 6 Feb 2025CISA SSVC assessment: exploitation active926 days (about 3 years) later
- 21 Oct 2025CVE record last updated257 days (about 9 months) later
- 12 Nov 2026Analysed by vulneraibility.com387 days (about 1 year) later
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
| Metric | Value | What it means |
|---|---|---|
| Attack vector | NetworkReachable over the internet or any routable network. | Reachable over the internet or any routable network. |
| Attack complexity | LowRepeatable attack, no special conditions. | Repeatable attack, no special conditions. |
| Privileges required | NoneThe attacker needs no prior access. | The attacker needs no prior access. |
| User interaction | NoneNo victim action needed. | No victim action needed. |
| Scope | UnchangedImpact stays within the vulnerable component. | Impact stays within the vulnerable component. |
| Confidentiality | HighTotal data disclosure possible. | Total data disclosure possible. |
| Integrity | HighComplete modification possible. | Complete modification possible. |
| Availability | HighFull outage possible. | Full outage possible. |
Common questions
Is CVE-2020-2509 being exploited?
Yes. CVE-2020-2509 appears in CISA's Known Exploited Vulnerabilities catalog, which means exploitation in the wild has been confirmed and reported. Treat it as active rather than theoretical, and patch it ahead of higher-scoring vulnerabilities that carry no exploitation evidence.
How severe is CVE-2020-2509?
CVE-2020-2509 is rated Critical with a CVSS score of 9.8. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2020-2509?
Yes. A fix has been recorded for CVE-2020-2509. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2020-2509 affect?
CVE-2020-2509 affects qnap:qts, qnap:quts_hero. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
References
Where the data on this page comes from
- CVE List (CVE.org): description, affected versions, references; CVE Terms of Use
- NVD: CVSS and CPE data
- CISA KEV catalog: exploitation, date added, due date
- CISA Vulnrichment (ADP): SSVC decision points
- FIRST EPSS: exploit probability and percentile
- PoC-in-GitHub: GitHub repositories that claim a proof of concept
Summary, impact and triage tags: written by our AI analysis pipeline from the sources above. Check them against the sources.
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