CVE-2025-66644
Published: 05 December 2025
Summary
CVE-2025-66644 is a high-severity OS Command Injection (CWE-78) vulnerability in Arraynetworks Arrayos Ag. Its CVSS base score is 7.2 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 18.4% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog.
The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and SI-2 (Flaw Remediation).
Threat & Defense at a Glance
Threat & Defense Details
Mitigating Controls (NIST 800-53 r5)AI
Directly remediates the command injection vulnerability by requiring timely application of vendor patches, such as upgrading to ArrayOS AG 9.4.5.9 or later.
Prevents command injection attacks by validating and sanitizing user inputs to block execution of arbitrary commands, directly addressing CWE-78.
Enforces least privilege to minimize accounts with the high privileges (PR:H) required for exploitation, reducing the attack surface on ArrayOS AG systems.
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Command injection in network-accessible VPN appliance enables exploitation of public-facing application (T1190) and facilitates webshell deployment as observed in real-world attacks (T1100).
NVD Description
Array Networks ArrayOS AG before 9.4.5.9 allows command injection, as exploited in the wild in August through December 2025.
Deeper analysisAI
CVE-2025-66644 is a command injection vulnerability (CWE-78) affecting Array Networks ArrayOS AG versions prior to 9.4.5.9. This flaw allows attackers to execute arbitrary commands on the affected system. The vulnerability received a CVSS v3.1 base score of 7.2 (AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H), indicating high severity due to its potential for significant impact on confidentiality, integrity, and availability following network-based exploitation with low complexity but requiring high privileges.
Exploitation requires an attacker to have high-level privileges (PR:H) on the target system, such as an authenticated administrative user. Once exploited, attackers can achieve full system compromise, including high impacts across confidentiality, integrity, and availability. In real-world attacks observed from August through December 2025, threat actors leveraged this vulnerability to deploy webshells on ArrayOS AG VPN appliances.
Advisories recommend upgrading to ArrayOS AG version 9.4.5.9 or later to mitigate the vulnerability. The flaw is listed in the CISA Known Exploited Vulnerabilities Catalog, mandating patching by federal agencies. Additional guidance appears in JPCERT advisory AT-2025-0024 and an Array Networks support announcement.
This vulnerability has seen active in-the-wild exploitation, as documented by multiple sources including BleepingComputer reports on webshell deployments.
Details
- CWE(s)
- KEV Date Added
- 08 December 2025