IRONSMITHINTEL
CRITICALCVSS9.8
|
Actively Exploited
|CISA KEV|CVE-2021-36380|Auth: none — unauthenticated|Reboot: required|Manual only

Sunhillo SureLine OS Command Injection Vulnerablity

Sunhillo SureLine contains an OS command injection vulnerability that allows an attacker to cause a denial-of-service or utilize the device for persistence on the network via shell metacharacters in ipAddr or dnsAddr in /cgi/networkDiag.cgi.

Published Aug 13, 2021 · Updated May 16, 2026
Why patchRisk explained in plain English
Worst-case scenarioIf unpatched

A remote attacker, without authentication, can achieve full data confidentiality loss, arbitrary modification of data, complete denial of service or system unavailability. Federal agencies are required to remediate by 2024-03-26 under CISA BOD 22-01.

How the attack worksNo clicks needed

This is a OS Command Injection (CWE-78) vulnerability in Sunhillo SureLine. Exploitation requires remote network access, low attack complexity, no authentication required, and no user interaction required.

📧

Phishing link

🖼

Malicious file

🔓

Server compromised

Am I affected?Quick check

Probably yes if any of these apply:

IT Security
Running sureline: v < 8.7.0.1.1
Real-world incidentsWhat we've seen

Active exploitation documented in the wild. Threat-research write-up: https://research.nccgroup.com/2021/07/26/technical-advisory-sunhillo-sureline-unauthenticated-os-command-injection-cve-2021-36380/

How to patch

Manual remediation steps

Apply the Vendor Patch

This vulnerability is in the CISA Known Exploited Vulnerabilities catalog — apply the vendor's security update as soon as possible.

CISA required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

References

    1
    Vendor advisory: https://www.sunhillo.com/fb011/
    1
    NVD entry: https://nvd.nist.gov/vuln/detail/CVE-2021-36380
    1
    CISA KEV: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-36380
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