How severe is CVE-2021-33842?

CVE-2021-33842 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-33842 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (34th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-33842?

CVE-2021-33842 affects Circutor Sge-plc1000 Firmware. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-33842?

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

When was CVE-2021-33842 published?

CVE-2021-33842 was published on 2021-06-09 and last updated on 2026-06-17.

CVE-2021-33842

CVE-2021-33842 is a high-severity vulnerability in Circutor Sge-plc1000 Firmware with a CVSS 3.x base score of 8.8. 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-565.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v2: 7.7
EPSS exploit prediction: 0% (34th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-565
Affected product: Circutor Sge-plc1000 Firmware
Published: 2021-06-09
Last modified: 2026-06-17

Description

Improper Authentication vulnerability in the cookie parameter of Circutor SGE-PLC1000 firmware version 0.9.2b allows an attacker to perform operations as an authenticated user. In order to exploit this vulnerability, the attacker must be within the network where the device affected is located.

Frequently asked questions

What is CVE-2021-33842?: Improper Authentication vulnerability in the cookie parameter of Circutor SGE-PLC1000 firmware version 0.9.2b allows an attacker to perform operations as an authenticated user. In order to exploit this vulnerability, the attacker must be within the network where the device affected is located.
How severe is CVE-2021-33842?: CVE-2021-33842 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-33842 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (34th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-33842?: CVE-2021-33842 affects Circutor Sge-plc1000 Firmware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-33842?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-33842 published?: CVE-2021-33842 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-improper-authentication

Affected products (1)

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

More vulnerabilities in Circutor Sge-plc1000 Firmware

CVE-2021-33841 — Critical (CVSS 10.0): SGE-PLC1000 device, in its 0.9.2b firmware version, does not handle some requests correctly, allowing a remote attacker…
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…

All CVEs affecting Circutor Sge-plc1000 Firmware →

Other CWE-565 vulnerabilities

CVE-2023-41084 — Critical (CVSS 10.0): Session management within the web application is incorrect and allows attackers to steal session cookies to perform a…
CVE-2014-125112 — Critical (CVSS 9.8): Plack::Middleware::Session::Cookie versions through 0.21 for Perl allows remote code…
CVE-2022-50926 — Critical (CVSS 9.8): WAGO 750-8212 PFC200 G2 2ETH RS firmware contains a privilege escalation vulnerability that allows attackers to…
CVE-2025-65212 — Critical (CVSS 9.8): An issue was discovered in NJHYST HY511 POE core before 2.1 and plugins before 0.1. The vulnerability stems from the…
CVE-2025-14440 — Critical (CVSS 9.8): The JAY Login & Register plugin for WordPress is vulnerable to authentication bypass in versions up to, and including,…
CVE-2025-2395 — Critical (CVSS 9.8): The U-Office Force from e-Excellence has an Improper Authentication vulnerability, allowing unauthenticated remote…

Browse all CWE-565 vulnerabilities →