CVE-2021-20139 json
An unauthenticated command injection vulnerability exists in the parameters of operation 3 in the controller_server service on Gryphon Towe…
published 2021-12-09 4 y ago modified 2026-06-17 4 mo ago also EUVD-2021-7596
- cvss
- 8.8
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 4.0%
- EPSS 4.0% chance of exploitation in 30 days, percentile 90%
- public exploits
- 0
- none known
Summary
An unauthenticated command injection vulnerability exists in the parameters of operation 3 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.
Exploit prediction
3.98% chance of exploitation in the next 30 days, higher than 90% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- tenable.com https://www.tenable.com/security/research/tra-2021-51 referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 8.8 | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVD | 2.0 | 8.3 | AV:A/AC:L/Au:N/C:C/I:C/A:C |
Affected products
- n/a Gryphon Tower router
Classification
- Weakness
-
- CWE-78 Improper Neutralization of Special Elements used in an OS Command
References
-
tenable.com
/security/research/tra-2021-51
exploit, vendor-advisory
Sources
- CVE List CVE-2021-20139
- NVD CVE-2021-20139
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