Cyber Resilience

CVE-2025-8693

RCE in Zyxel Ex3300-T0 Firmware ≤ 5.50\(abvy.6.3\)c0

Published
18 November 2025
Modified
15 December 2025
Patch / advisory
CVSS Score v3.1 8.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.011 62th percentile
Risk Priority 66 floored blend · peak EPSS

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 Command and Scripting Interpreter (T1059); ranked in the top 38% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

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.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

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 Techniques

T1059 Command and Scripting Interpreter Execution
Adversaries may abuse command and script interpreters to execute commands, scripts, or binaries.
T1059.003 Windows Command Shell Execution
Adversaries may abuse the Windows command shell for execution.
T1059.004 Unix Shell Execution
Adversaries may abuse Unix shell commands and scripts for execution.
T1059.001 PowerShell Execution
Adversaries may abuse PowerShell commands and scripts for execution.
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2025-13943Same product: Zyxel Ax7501-B1
CVE-2026-0711Same product: Zyxel Ax7501-B0
CVE-2026-1460Same product: Zyxel Ax7501-B1
CVE-2025-13942Same product: Zyxel Dx4510-B1
CVE-2026-1459Same product: Zyxel Dx5401-B1
CVE-2024-9200Same product: Zyxel Vmg4005-B50A
CVE-2023-27991Same vendor: Zyxel
CVE-2024-40890Same vendor: Zyxel
CVE-2024-29972Same vendor: Zyxel
CVE-2024-6342Same vendor: Zyxel

Affected Assets

zyxel
dm4200-b0 firmware
≤ 5.17\(acbs.1.3\)c0
zyxel
dx3300-t0 firmware
≤ 5.50\(abvy.6.3\)c0
zyxel
dx3300-t1 firmware
≤ 5.50\(abvy.6.3\)c0
zyxel
dx3301-t0 firmware
≤ 5.50\(abvy.6.3\)c0
zyxel
dx4510-b1 firmware
≤ 5.17\(abyl.9\)c0
zyxel
dx5401-b0 firmware
≤ 5.17\(abyo.7\)b2
zyxel
dx5401-b1 firmware
≤ 5.17\(abyo.7\)b2
zyxel
ee3301-00 firmware
≤ 5.63\(acmu.1.1\)c0
zyxel
ee5301-00 firmware
≤ 5.63\(acld.1.1\)c0
zyxel
ee6510-10 firmware
≤ 5.19\(acjq.3\)c0
+44 more product configuration(s) — see NVD for full list

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V1.2.5
  • V1.2.8
  • V15.2.5

Mitigating Controls (NIST 800-53 r5) AI

Developer testing and evaluation can discover missing or incorrect command sanitization during development.

Input validation directly neutralizes or rejects special characters that would otherwise alter OS command structure.

Least privilege reduces the permissions available to any process that could be subverted by injected commands.

Least functionality restricts available OS commands and interpreters, limiting the blast radius of injection.

Secure engineering principles require proper neutralization of untrusted input before command construction.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

PR.PS-06's SDLC practices directly require secure coding and input handling that blocks command-injection defects, yet the single broad outcome leaves many specific neutralization vectors and verification gaps unaddressed.

PR.PS-02 partial match
prevents

Routine patching/maintenance can remediate known command-injection CVEs in dependencies (partial forward) but does nothing to stop developers from introducing improper neutralization in custom code (none reverse).

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

finds

Security testing and code review target insecure use of operating-system command interfaces, catching command-injection flaws introduced during development.

References