How severe is CVE-2021-33841?

CVE-2021-33841 has a CVSS 3.x base score of 10.0, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-33841 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (82nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-33841?

CVE-2021-33841 affects Circutor Sge-plc1000 Firmware. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-33841?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2021-33841 published?

CVE-2021-33841 was published on 2021-06-09 and last updated on 2026-06-17.

CVE-2021-33841

CVE-2021-33841 is a critical-severity vulnerability in Circutor Sge-plc1000 Firmware with a CVSS 3.x base score of 10.0. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-78.

Key facts

Severity: Critical (CVSS 3.x base score 10.0)
CVSS v2: 10.0
EPSS exploit prediction: 2% (82nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-78
Affected product: Circutor Sge-plc1000 Firmware
Published: 2021-06-09
Last modified: 2026-06-17

Description

SGE-PLC1000 device, in its 0.9.2b firmware version, does not handle some requests correctly, allowing a remote attacker to inject code into the operating system with maximum privileges.

Frequently asked questions

What is CVE-2021-33841?: SGE-PLC1000 device, in its 0.9.2b firmware version, does not handle some requests correctly, allowing a remote attacker to inject code into the operating system with maximum privileges.
How severe is CVE-2021-33841?: CVE-2021-33841 has a CVSS 3.x base score of 10.0, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-33841 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (82nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-33841?: CVE-2021-33841 affects Circutor Sge-plc1000 Firmware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-33841?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2021-33841 published?: CVE-2021-33841 was published on 2021-06-09 and last updated on 2026-06-17.

References

https://www.incibe.es/en/incibe-cert/notices/aviso-sci/circutor-sge-plc1000-os-command-injection

Affected products (1)

cpe:2.3:o:circutor:sge-plc1000_firmware:0.9.2b:*:*:*:*:*:*:*

More vulnerabilities in Circutor Sge-plc1000 Firmware

CVE-2025-11788 — Critical (CVSS 9.8): Heap-based buffer overflow vulnerability in Circutor SGE-PLC1000/SGE-PLC50 v9.0.2. In the 'ShowSupervisorParameters()'…
CVE-2025-11786 — Critical (CVSS 9.8): Stack-based buffer overflow vulnerability in Circutor SGE-PLC1000/SGE-PLC50 v9.0.2. In the 'SetUserPassword()'…
CVE-2025-11785 — Critical (CVSS 9.8): Stack-based buffer overflow vulnerability in Circutor SGE-PLC1000/SGE-PLC50 v9.0.2. In the 'ShowMeterPasswords()'…
CVE-2025-11784 — Critical (CVSS 9.8): Stack-based buffer overflow vulnerability in Circutor SGE-PLC1000/SGE-PLC50 v9.0.2. In the 'ShowMeterDatabase()'…
CVE-2025-11783 — Critical (CVSS 9.8): Stack-based buffer overflow vulnerability in Circutor SGE-PLC1000/SGE-PLC50 v9.0.2. The vulnerability is found in the…
CVE-2025-11782 — Critical (CVSS 9.8): Stack-based buffer overflow vulnerability in Circutor SGE-PLC1000/SGE-PLC50 v9.0.2. The 'ShowDownload()' function uses…

All CVEs affecting Circutor Sge-plc1000 Firmware →

Other CWE-78 (OS Command Injection) vulnerabilities

CVE-2026-19188 — Critical (CVSS 10.0): A critical OS command injection vulnerability has been identified in the Haiwell IoT Cloud HMI Gateway product. The…
CVE-2026-48362 — Critical (CVSS 10.0): ColdFusion is affected by an Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')…
CVE-2026-16812 — Critical (CVSS 10.0): VeloCloud Orchestrator (VCO) on-prem has a security issue where this issue may allow a remote attacker to access…
CVE-2026-6516 — Critical (CVSS 10.0): Zohocorp ManageEngine ADAudit Plus versions before 8606 are affected by Unauthenticated Remote code execution due to…
CVE-2026-46339 — Critical (CVSS 10.0): 9Router is an AI router & token saver. From 0.4.30 until 0.4.37, 9Router's src/proxy.js middleware did not protect…
CVE-2026-59726 — Critical (CVSS 10.0): Ruflo is an agent meta-harness for Claude Code and Codex. Prior to 3.16.3, ruflo's default docker-compose deployment…

Browse all CWE-78 (OS Command Injection) vulnerabilities →