CVE-2021-35394: listed in the CISA KEV catalog

CVE-2021-35394 · CVSS 9.8 CRITICAL · EPSS 99.9% · KEV 2021-12-10

Realtek Jungle SDK version v2.x up to v3.4.14B provides a diagnostic tool called 'MP Daemon' that is usually compiled as 'UDPServer' binary. The binary is affected by multiple memory corruption vulnerabilities and an arbitrary command injection vulnerability that can be exploited by remote unauthenticated attackers.

Is CVE-2021-35394 exploited?

• Listed in the CISA KEV catalog on 2021-12-10.
• Federal remediation due 2021-12-24.
• Past that date by 1746 days.
• EPSS puts exploitation in the next 30 days at 99.9%.
• Public exploit code: none found in monitored sources.
• Public detection rules exist.

Which products and versions are affected?

• realtek · rtl819x jungle software development kit · >= 2.0, <= 3.4.14b

Is there a patch?

No patch identifier recorded here yet.

What PlainSec published about CVE-2021-35394

• Cling Uses STUN Traffic to Hide Router Exploits (2026-10-05)

Primary sources

• NVD record
• CISA KEV catalog
• Nuclei template

What this record does not say

• No patch identifier.

KEV and EPSS are re-checked daily. Record last updated 2026-10-05.