Cyber Resilience

CVE-2021-26747

RCE in Netis-Systems Wf2780 Firmware 2.3.40404

Public PoCHigh EPSSRCECommand Injection
Published
18 February 2021
Modified
21 November 2024
Patch / advisory
View advisory
CVSS Score v3.1 9.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.54 99th percentile
Risk Priority 86 floored blend · peak EPSS

Summary

CVE-2021-26747 is a critical-severity OS Command Injection (CWE-78) vulnerability in Netis-Systems Wf2780 Firmware. Its CVSS base score is 9.8 (Critical).

Operationally, ranked in the top 1% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

OWASP Top 10 for Web (2025)

A05:2025 Injection

EU & UK References

Vulnerability Data

Netis WF2780 2.3.40404 and WF2411 1.1.29629 devices allow Shell Metacharacter Injection into the ping command, leading to remote code execution.

CWE(s)
CWE-78

Related Threats

Likely ATT&CK TechniquesAI

Techniques this vulnerability likely enables, inferred from its description, weakness type, and attributed-actor tradecraft. Confidence is per-technique.

T1190 Exploit Public-Facing Application Initial Accessconfidence: HIGH
Shell metacharacter injection in the ping command on a public-facing router enables remote code execution via the web interface.
attack.mitre.org →
T1059.004 Unix Shell Executionconfidence: HIGH
The vulnerability allows direct injection of shell metacharacters, enabling execution of arbitrary Unix shell commands.
attack.mitre.org →
inferred from description + CWE · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2024-25851Same product: Netis-Systems Wf2780
CVE-2019-19356Same vendor: Netis-Systems
CVE-2023-45467Same vendor: Netis-Systems
CVE-2023-43893Same vendor: Netis-Systems
CVE-2024-25850Same product: Netis-Systems Wf2780
CVE-2024-33793Same vendor: Netis-Systems
CVE-2023-43890Same vendor: Netis-Systems
CVE-2025-50635Same product: Netis-Systems Wf2780
CVE-2023-43892Same vendor: Netis-Systems
CVE-2024-33792Same vendor: Netis-Systems

Affected Assets

netis-systems
wf2780 firmware
2.3.40404
netis-systems
wf2411 firmware
1.1.29629

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
detects

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

References