Predictive Vulnerability Intelligence.

Product

  • Product
  • Pricing
  • Documentation

Company

  • About
  • Partnerships
  • Blog
  • Support

Legal

  • Terms
  • Privacy
  • Data Licensing

© 2026 FAUCET Technologies LLC. All rights reserved.

CVE-2020-2509

83
FAUCET Score

CVE-2020-2509 is a critical command injection vulnerability affecting QNAP QTS and QuTS hero network-attached storage (NAS) devices. This flaw allows unauthenticated attackers to execute arbitrary commands, leading to complete compromise of the affected system. With a CVSS score of 9.8 (Critical) and an EPSS score indicating high exploitability, this vulnerability poses a significant risk due to its network-based attack vector and low attack complexity. It is actively exploited in the wild, as confirmed by its inclusion in CISA's KEV catalog, and has garnered substantial community discussion and media attention, including its use in ransomware attacks.

Impacted Technologies

VendorProductVersion(s)CPE
< 4.2.6CPE matchmatch criteria
cpe:2.3:o:qnap:qts:*:*:*:*:*:*:*:*
>= 4.3.5, < 4.3.6CPE matchmatch criteria
cpe:2.3:o:qnap:qts:*:*:*:*:*:*:*:*
>= 4.4.0, < 4.5.1CPE matchmatch criteria
cpe:2.3:o:qnap:qts:*:*:*:*:*:*:*:*
4.2.6CPE matchmatch criteria
cpe:2.3:o:qnap:qts:4.2.6:-:*:*:*:*:*:*
4.2.6CPE matchmatch criteria
cpe:2.3:o:qnap:qts:4.2.6:build_20170517:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 3.1

9.8CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
Exploitability Score
3.9
Impact Score
5.9
CvssVersion
3.1

Exploit Intelligence

EPSS Score
33.38%
Probability of exploitation in next 30 days
EPSS Percentile
98.2%
Percentile rank of EPSS score among Peer Group
As of 2026-07-27
Model: v2026.06.15
Added to KEV · Apr 11, 2022
This CVE's current EPSS score of 0.3338 is in the 95th percentile among its peer group of 36,835 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.1 Reddit, 0.3 Bluesky, 0.3 Mastodon, and 2.4 GitHub mentions.

Media Mentions

The average CVE in this peer group has 0.3 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Remediation records are not available for this CVE.

References

cisa.gov / known-exploited-vulnerabilities-catalog
US Government Resource
qnap.com / en/security-advisory/qsa-21-05
Vendor Advisory