CVE-2021-36380
CriticalExploitedPublic exploitSunhillo SureLine before 8.7.0.1.1 allows Unauthenticated OS Command Injection via shell metacharacters in ipAddr or dnsAddr /cgi/networkDiag.cgi.
Published Aug 13, 2021 · Updated Nov 5, 2025
Key Facts
Patch immediately- CVE-2021-36380 is a critical-severity vulnerability (CVSS 9.8 v3.1) affecting Sureline (Sunhillo).
- It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Oct 9, 2023. Public exploit code is available.
- EPSS estimates a 98% probability of exploitation in the next 30 days.
- Fixed versions are available, including Sureline 8.7.0.1.1.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v3.1
9.8
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS (30-day exploit likelihood)
98%
Higher than 99.9% of all scored CVEs
Exploited in the wild
Yes
4 catalog listings
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2021-36380 brief as a PDF
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Description
Sunhillo SureLine before 8.7.0.1.1 allows Unauthenticated OS Command Injection via shell metacharacters in ipAddr or dnsAddr /cgi/networkDiag.cgi.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| CISA KEV | Mar 5, 2024 | Mar 26, 2024 | Not reported |
| Industry KEV feed | Oct 9, 2023 | Mar 26, 2024 | Not reported |
| CIRCL KEV | Oct 13, 2023 | Mar 26, 2024 | Not reported |
| ENISA EUVD | Mar 5, 2024 | n/a | Not reported |
Required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Affected Products
1 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| SurelineSunhillo | See advisory | 8.7.0.1.1 |
Patched Releases
Sureline
8.7.0.1.1
Timeline
Publicly disclosed
Aug 13, 2021
Added to Industry KEV feed
Oct 9, 2023
Added to CIRCL KEV
Oct 13, 2023
Added to CISA KEV
Mar 5, 2024
Added to ENISA EUVD
Mar 5, 2024
Last updated
Nov 5, 2025
Weakness Type
- CWE-78 Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
References
- exploitVulnCheck exploitation report
- exploitVulnCheck exploitation report
- exploitVulnCheck exploitation report
- exploitVulnCheck exploitation report
- exploitVulnCheck exploitation report
FAQ
Common Questions.
Sunhillo SureLine before 8.7.0.1.1 allows Unauthenticated OS Command Injection via shell metacharacters in ipAddr or dnsAddr /cgi/networkDiag.cgi.
Affected: Sureline (Sunhillo). The full list is in the CVE brief.
It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Oct 9, 2023.
Yes. It was added on Mar 5, 2024 with a federal remediation due date of Mar 26, 2024.
Public exploit code is available.
Fixed versions are available, including Sureline 8.7.0.1.1.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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