CVE-2025-8693
Published: 18 November 2025
Summary
CVE-2025-8693 is a high-severity OS Command Injection (CWE-78) vulnerability in Zyxel Ex3300-T0 Firmware. Its CVSS base score is 8.8 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Network Device CLI (T1059.008); ranked at the 32.1th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and SI-2 (Flaw Remediation).
Deeper analysis
CVE-2025-8693 is a post-authentication command injection vulnerability (CWE-78) in the "priv" parameter of Zyxel DX3300-T0 firmware version 5.50(ABVY.6.3)C0 and earlier. This flaw allows an authenticated attacker to execute arbitrary operating system commands on the affected device. The vulnerability carries a CVSS v3.1 base score of 8.8 (AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H) and was published on 2025-11-18T02:15:45.410.
An attacker with low-privilege authenticated access (PR:L) can exploit this vulnerability remotely over the network (AV:N) with low attack complexity (AC:L) and without requiring user interaction (UI:N). Successful exploitation enables execution of OS commands, resulting in high impacts to confidentiality, integrity, and availability (C:H/I:H/A:H), potentially leading to full device compromise.
The Zyxel security advisory provides details on mitigation, available at https://www.zyxel.com/global/en/support/security-advisories/zyxel-security-advisory-for-uncontrolled-resource-consumption-and-command-injection-vulnerabilities-in-certain-4g-lte-5g-nr-cpe-dsl-ethernet-cpe-fiber-onts-security-routers-and-wireless-extenders-11-18-2025.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-197902
Vulnerability details
A post-authentication command injection vulnerability in the "priv" parameter of Zyxel DX3300-T0 firmware version 5.50(ABVY.6.3)C0 and earlier could allow an authenticated attacker to execute operating system (OS) commands on an affected device.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Post-authentication command injection in network device firmware directly enables arbitrary OS command execution (T1059.008: Network Device CLI) through exploitation of a remote management service (T1210: Exploitation of Remote Services).
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Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly validates inputs like the 'priv' parameter to block command injection payloads from executing OS commands.
Mandates timely patching of the specific firmware flaw enabling post-authentication command injection.
Enforces least privilege for authenticated low-privilege users to limit the scope and impact of injected OS commands.