How severe is CVE-2021-20141?

CVE-2021-20141 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-2021-20141 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (88th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-20141?

CVE-2021-20141 affects Gryphonconnect Gryphon Tower Firmware. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-20141?

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-2021-20141 published?

CVE-2021-20141 was published on 2021-12-09 and last updated on 2026-06-17.

CVE-2021-20141

CVE-2021-20141 is a high-severity vulnerability in Gryphonconnect Gryphon Tower 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-78.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v2: 8.3
EPSS exploit prediction: 4% (88th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-78
Affected product: Gryphonconnect Gryphon Tower Firmware
Published: 2021-12-09
Last modified: 2026-06-17

Description

An unauthenticated command injection vulnerability exists in the parameters of operation 32 in the controller_server service on Gryphon Tower routers. An unauthenticated remote attacker on the same network can execute commands as root on the device by sending a specially crafted malicious packet to the controller_server service on port 9999.

Frequently asked questions

What is CVE-2021-20141?: An unauthenticated command injection vulnerability exists in the parameters of operation 32 in the controller_server service on Gryphon Tower routers. An unauthenticated remote attacker on the same network can execute commands as root on the device by sending a specially crafted malicious packet to the controller_server service on port 9999.
How severe is CVE-2021-20141?: CVE-2021-20141 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-2021-20141 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (88th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-20141?: CVE-2021-20141 affects Gryphonconnect Gryphon Tower Firmware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-20141?: 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-2021-20141 published?: CVE-2021-20141 was published on 2021-12-09 and last updated on 2026-06-17.

References

https://www.tenable.com/security/research/tra-2021-51

Affected products (1)

cpe:2.3:o:gryphonconnect:gryphon_tower_firmware:*:*:*:*:*:*:*:*

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CVE-2021-20144 — High (CVSS 8.8): An unauthenticated command injection vulnerability exists in the parameters of operation 49 in the controller_server…
CVE-2021-20143 — High (CVSS 8.8): An unauthenticated command injection vulnerability exists in the parameters of operation 48 in the controller_server…
CVE-2021-20142 — High (CVSS 8.8): An unauthenticated command injection vulnerability exists in the parameters of operation 41 in the controller_server…
CVE-2021-20140 — High (CVSS 8.8): An unauthenticated command injection vulnerability exists in the parameters of operation 10 in the controller_server…
CVE-2021-20139 — High (CVSS 8.8): An unauthenticated command injection vulnerability exists in the parameters of operation 3 in the controller_server…

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