CVE-2020-2509

CRITICAL(9.8)KEVElevated Risk

QNAP Network-Attached Storage (NAS) Command Injection Vulnerability

Description

CVE-2020-2509 is a command injection vulnerability in QNAP NAS devices that allows remote attackers to execute arbitrary commands on affected systems. The flaw exists in the web management interface and can be exploited without authentication in certain configurations. This vulnerability has been added to CISA's Known Exploited Vulnerabilities (KEV) catalog, confirming active exploitation in the wild. With a high EPSS score of 19.8% (96th percentile), this vulnerability represents a significant threat to organizations running unpatched QNAP NAS devices.

KEV Information

Vendor
QNAP
Product
QNAP Network-Attached Storage (NAS)
Date Added
April 11, 2022
Due Date
May 2, 2022
Required Action
Apply updates per vendor instructions.

CVSS Score

Vector String
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HOpen in Calculator
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

CWEs

Affected Products

VendorProductVersion
qnapqts< 4.2.6; >= 4.3.5, < 4.3.6; >= 4.4.0, < 4.5.1; 4.2.6; 4.3.3.0174; 4.3.3.0868; 4.3.3.0998; 4.3.3.1051; 4.3.3.1098; 4.3.3.1161; 4.3.3.1252; 4.3.3.1315; 4.3.3.1386; 4.3.3.1432; 4.3.4.0358; 4.3.4.0370; 4.3.4.0372; 4.3.4.0374; 4.3.4.0387; 4.3.4.0411; 4.3.4.0416; 4.3.4.0427; 4.3.4.0434; 4.3.4.0435; 4.3.4.0451; 4.3.4.0483; 4.3.4.0486; 4.3.4.0506; 4.3.4.0516; 4.3.4.0526; 4.3.4.0551; 4.3.4.0557; 4.3.4.0561; 4.3.4.0569; 4.3.4.0593; 4.3.4.0597; 4.3.4.0604; 4.3.4.0899; 4.3.4.1029; 4.3.4.1082; 4.3.4.1190; 4.3.4.1282; 4.3.4.1368; 4.3.4.1417; 4.3.4.1463; 4.3.6; 4.3.6.0895; 4.3.6.0907; 4.3.6.0923; 4.3.6.0944; 4.3.6.0959; 4.3.6.0979; 4.3.6.0993; 4.3.6.1013; 4.3.6.1033; 4.3.6.1070; 4.3.6.1154; 4.3.6.1218; 4.3.6.1263; 4.3.6.1286; 4.3.6.1333; 4.3.6.1411; 4.3.6.1446; 4.5.1; 4.5.1.1456; 4.5.1.1461; 4.5.1.1465; 4.5.1.1480; 4.5.2
qnapquts hero< h4.5.1; h4.5.1; h4.5.1.1472

Multiple CVSS Assessments

Source: [email protected](Primary)
9.8
CRITICAL

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

Source: 134c704f-9b21-4f2e-91b3-4a467353bcc0(Secondary)
9.8
CRITICAL

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

References

Weakness Type

CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')

OS command injection occurs when an application constructs system commands using unsanitized user input, allowing attackers to inject and execute arbitrary operating system commands. In CVE-2020-2509, the QNAP NAS web interface fails to properly sanitize user-supplied input before passing it to system shell commands. For more details, see CWE-78.

Impact Analysis

Successful exploitation of this vulnerability grants attackers the ability to execute arbitrary commands with the privileges of the web server process on the QNAP NAS device. This can lead to complete device compromise, including unauthorized access to all stored data, modification or deletion of files, installation of backdoors or malware, and use of the NAS as a pivot point for further attacks within the network. Given that NAS devices typically store sensitive organizational data and backups, compromise of these systems can result in significant data breaches and potential ransomware deployment against critical backup infrastructure.

Exploit Maturity

CVE-2020-2509 has been confirmed as actively exploited and was added to CISA's Known Exploited Vulnerabilities catalog on April 11, 2022. The high EPSS score of 19.8% (96th percentile) indicates significant exploitation activity and broad attacker interest. QNAP NAS devices are frequently targeted by threat actors including ransomware operators due to their widespread use in enterprise environments and the valuable data they typically contain.

Remediation

  1. Update QNAP QTS and QuTS hero firmware to the latest patched versions as specified in QNAP security advisory QSA-21-05, which is the required action per CISA's KEV catalog.
  2. Restrict management interface access to trusted networks only by configuring firewall rules to block external access to the NAS admin interface on ports 443 and 8080.
  3. Enable and configure QNAP's built-in firewall and access control features to limit connections to authorized IP addresses.
  4. Implement network segmentation to isolate NAS devices from the broader network, reducing the potential impact of compromise.
  5. Review NAS access logs for signs of unauthorized access or suspicious command execution patterns.

Technical Details

The vulnerability exists in the web server component of QNAP NAS firmware, where certain HTTP request parameters are passed to system shell commands without adequate input sanitization. An attacker can craft malicious HTTP requests containing shell metacharacters that break out of the intended command context and inject additional operating system commands. The injected commands execute with the privileges of the web server process, which on QNAP NAS devices typically runs with elevated permissions sufficient to access all stored data and modify system configurations. The attack vector is network-based and in some configurations does not require authentication, making it particularly dangerous for internet-exposed devices.

Frequently Asked Questions

What is CVE-2020-2509?

CVE-2020-2509 is a command injection vulnerability in the web management interface of QNAP NAS devices. It allows remote attackers to execute arbitrary operating system commands on affected devices, potentially leading to complete system compromise.

Which QNAP products are affected?

The vulnerability affects QNAP QTS and QuTS hero firmware versions prior to the patched releases documented in QNAP security advisory QSA-21-05. Check the QNAP security advisory for specific version numbers applicable to your device model.

Can this vulnerability be exploited remotely?

Yes, this is a remotely exploitable vulnerability that targets the web management interface. If the NAS management interface is accessible from the internet, it can be exploited by any remote attacker. Even within internal networks, any user with network access to the management interface can potentially exploit it.

Are there ransomware campaigns targeting this vulnerability?

While the KEV catalog lists the ransomware association as unknown for this specific CVE, QNAP NAS devices have been heavily targeted by ransomware campaigns including DeadBolt and Qlocker. Organizations should treat this vulnerability with high urgency regardless of specific ransomware associations.

CVSS Score

9.8
CRITICAL(9.8)

EPSS Score

EPSS Score33.38%
EPSS Percentile98.2%

Dates

PublishedApril 17, 2021
Last ModifiedJune 17, 2026
StatusAnalyzed
CVSS Versionv3.1

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