Cyber Resilience

CVE-2017-6884

RCE in Zyxel Emg2926 Firmware v1.00\(aaqt.4\)b8

CISA KEVActive ExploitationEUVD ExploitedPublic PoCRansomware-linkedRCECommand Injection
Published
06 April 2017
Modified
04 August 2026
KEV Added
18 September 2023
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 0.38 98th percentile
Risk Priority 90 floored blend · peak EPSS

Summary

CVE-2017-6884 is a high-severity OS Command Injection (CWE-78) vulnerability in Zyxel Emg2926 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 2% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog; a public proof-of-concept is referenced.

Deeper analysis AI-assisted summary

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

A command injection vulnerability, tracked as CVE-2017-6884 and assigned CWE-78, affects the Zyxel EMG2926 home router running firmware V1.00(AAQT.4)b8. The flaw resides in the diagnostic tools, specifically the nslookup function, and can be triggered through parameters such as ping_ip submitted to the expert/maintenance/diagnostic/nslookup URI.

An authenticated remote attacker with network access can supply crafted input to execute arbitrary commands on the device. Successful exploitation yields full control over the router, resulting in high impact to confidentiality, integrity, and availability as reflected in the CVSS 8.8 score.

The vulnerability is listed in the CISA Known Exploited Vulnerabilities catalog, and public exploit code is available on Exploit-DB. No vendor advisory or patch details are provided in the supplied references.

OWASP Top 10 for Web (2025)

A05:2025 Injection

EU & UK References

Vulnerability Data

A command injection vulnerability was discovered on the Zyxel EMG2926 home router with firmware V1.00(AAQT.4)b8. The vulnerability is located in the diagnostic tools, specifically the nslookup function. A malicious user may exploit numerous vectors to execute arbitrary commands on the…

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router, such as the ping_ip parameter to the expert/maintenance/diagnostic/nslookup URI.

CWE(s)
CWE-78
KEV Date Added
18 September 2023

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.
attack.mitre.org →
T1059.003 Windows Command Shell Execution
Adversaries may abuse the Windows command shell for execution.
attack.mitre.org →
T1059.004 Unix Shell Execution
Adversaries may abuse Unix shell commands and scripts for execution.
attack.mitre.org →
T1059.001 PowerShell Execution
Adversaries may abuse PowerShell commands and scripts for execution.
attack.mitre.org →
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.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2024-40890Same vendor: Zyxelboth on KEV
CVE-2024-40891Same vendor: Zyxelboth on KEV
CVE-2022-30525Same vendor: Zyxelboth on KEV
CVE-2023-27992Same vendor: Zyxelboth on KEV
CVE-2020-9054Same vendor: Zyxelboth on KEV
CVE-2023-28771Same vendor: Zyxelboth on KEV
CVE-2017-18368Same vendor: Zyxelboth on KEV
CVE-2023-27991Same vendor: Zyxel
CVE-2024-29972Same vendor: Zyxel
CVE-2024-6342Same vendor: Zyxel

Affected Assets

zyxel
emg2926 firmware
v1.00\(aaqt.4\)b8

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

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

SC-27 Platform-independent Applications
addresses: CWE-78

Platform-independent apps typically execute inside a managed runtime or sandbox that restricts direct OS command execution, reducing the ability to exploit OS command injection.

SI-10 Information Input Validation
addresses: CWE-78

Validates inputs to block special elements that would alter OS command execution.

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.

A.8.29 Security testing in development and acceptance mostly match
finds

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

References