PatchTheCVECVE-2021-20140: An unauthenticated command injection vulnerability exists in the parameters of operation 10 in the controller_
CVE-2021-20140 is a high-severity flaw (CVSS 8.8) affecting gryphon tower firmware. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
An unauthenticated command injection vulnerability exists in the parameters of operation 10 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.
Why this priority
- High severity
- EPSS top 10%: very likely to be exploited
- Public exploit reference
A fixed release or distro patch exists.
Risk facts
| CVSS score | 8.8 (High) |
| Attack vector | Adjacent network |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 4.0% (top 10%) |
| CISA exploited list | No |
| Weakness | CWE-78 |
| Published | 2021-12-09 |
| Last modified | 2026-06-17 |
Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2021-20140?
gryphon tower firmware: upgrade to newer than 04.0004.12. Exact commands for each OS are on this page.
Is CVE-2021-20140 being exploited?
CVE-2021-20140 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2021-20140 affect?
CVE-2021-20140 affects gryphon tower firmware. Severity is high (CVSS 8.8). An unauthenticated command injection vulnerability exists in the parameters of operation 10 in the controller_server service on Gryphon Tower routers. An unauthenticated remote attacker on the same network can execute commands as root on th
How urgent is CVE-2021-20140?
Priority 58/100. High severity; EPSS top 10%: very likely to be exploited; Public exploit reference
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