Authenticated command execution via NTP server parameter
Published Dec 8, 2023 · Updated Oct 21, 2025
OS command injection in QNAP VioStor NVR QVR Firmware 4.x allows remote authenticated users to execute commands through its management interface. The server.cgi handler uses the SPECIFIC_SERVER value from an NTP-settings POST request without neutralizing shell metacharacters before command execution. Valid management credentials are required; captured attacks used weak default credentials to install Mirai-based malware and enlist recorders in a DDoS botnet.
Summary
What happened
OS command injection in QNAP VioStor NVR QVR Firmware 4.x allows remote authenticated users to execute commands through its management interface. The server.cgi handler uses the SPECIFIC_SERVER value from an NTP-settings POST request without neutralizing shell metacharacters before command execution. Valid management credentials are required; captured attacks used weak default credentials to install Mirai-based malware and enlist recorders in a DDoS botnet.
The record
- CVE
- CVE-2023-47565
- Published
- Dec 8, 2023
- Updated
- Oct 21, 2025
- Vendor
- Linn Products Limited
- Product
- VioStor NVR
- Classifications
- CWE-78, CAPEC-88, T1059.004, T1190
- Attack vector
- adjacent
- Privileges
- authenticated
Timeline
How it unfolded
- Dec 8, 2023CVE publishedPublication date reported by the CVE source.
- Dec 21, 2023Exploitation reportedCISA Known Exploited Vulnerabilities catalog listing
- Oct 21, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=4.x <5.0.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Captured VioStor SPECIFIC_SERVER exploitation requestfunctional · observed in use
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Reported exploitation
- InfectedSlurs Mirai botnet exploitationbotnet
- CISA Known Exploited Vulnerabilities catalog listingknown exploited catalog
Technologies
Your stack
See the directory against your own environment.
Your stack
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