Cyber Resilience

CVE-2025-28138

RCE in Totolink A800R Firmware 4.1.2cu.5137_b20200730

Published
27 March 2025
Modified
15 April 2025
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 0.010 60th percentile
Risk Priority 79 floored blend · peak EPSS

Summary

CVE-2025-28138 is a critical-severity OS Command Injection (CWE-78) vulnerability in Totolink A800R Firmware. Its CVSS base score is 9.8 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Command and Scripting Interpreter (T1059); ranked in the top 40% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

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-2025-28138 is a pre-authentication remote command execution vulnerability affecting the TOTOLINK A800R router running firmware version V4.1.2cu.5137_B20200730. The flaw resides in the setNoticeCfg function, where the NoticeUrl parameter is processed without adequate sanitization, enabling OS command injection as indicated by the associated CWE-78 classification. The issue carries a CVSS 3.1 score of 9.8, reflecting network-accessible exploitation with no required credentials or user interaction.

An unauthenticated remote attacker can supply a malicious NoticeUrl value to the affected endpoint and achieve arbitrary command execution on the device. Successful exploitation grants the attacker full control over the router, including the ability to read, modify, or delete data and disrupt device operation.

Public references consist of technical write-ups and proof-of-concept material hosted on GitHub and Notion; these sources do not include vendor advisories, firmware patches, or explicit mitigation guidance. The associated EPSS score rose from a low baseline to a peak of 0.0788 on 2026-02-03 before receding to its current value of 0.0379, indicating a period of increased exploitation interest following disclosure.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

The TOTOLINK A800R V4.1.2cu.5137_B20200730 were found to contain a pre-auth remote command execution vulnerability in the setNoticeCfg function through the NoticeUrl parameter.

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-2025-28017Same product: Totolink A800R
CVE-2025-28035Same product: Totolink A800R
CVE-2025-28034Same product: Totolink A800R
CVE-2025-28036Same product: Totolink A800R
CVE-2025-28136Same product: Totolink A800R
CVE-2025-28019Same product: Totolink A800R
CVE-2025-28020Same product: Totolink A800R
CVE-2025-28018Same product: Totolink A800R
CVE-2024-0292Same vendor: Totolink
CVE-2024-0298Same vendor: Totolink

Affected Assets

totolink
a800r firmware
4.1.2cu.5137_b20200730

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