How severe is CVE-2021-35394?

CVE-2021-35394 has a CVSS 3.1 base score of 9.8 (CRITICAL). EPSS estimates a 99.9% probability of exploitation in the next 30 days. It is listed in the CISA Known Exploited Vulnerabilities catalog.

CVE-2021-35394: Realtek Jungle SDK Remote Code Execution Vulnerability

CISA Known Exploited Vulnerabilities

Realtek Jungle SDK Remote Code Execution Vulnerability is confirmed as actively exploited and is listed in the CISA KEV catalog.

Added to KEV

2021-12-10

Remediation due

2021-12-24

Required action
Apply updates per vendor instructions.

CISA notes
https://nvd.nist.gov/vuln/detail/CVE-2021-35394

Description

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.

Severity

CVSS 3.1 · CISA9.8 CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

SSVC · CISA-ADP

Exploitationactive

Automatableyes

Technical impacttotal

Exploitation Context

as of October 13, 2026

All KEV statistics→

CISA added CVE-2021-35394 to the KEV catalog 116 days after its CVE record was published.
It is one of 3 Realtek entries in the CISA KEV catalog, and one of 2 added in 2021.
Its current EPSS score (99.9%) is higher than that of 92% of CISA KEV entries.

Affected Products

Vendor	Product	Affected versions
-	-	n/a

References

4 Links

Other references

Record Details

Published

2021-08-16

Last updated

2025-10-21

Assigner (CNA)

mitre

Credited to

CVE record data © The MITRE Corporation, used under the CVE Terms of Use. Exploited-in-the-wild data from the CISA Known Exploited Vulnerabilities catalog (CC0). Exploit prediction scores by FIRST EPSS (first.org/epss). This site is not endorsed or certified by MITRE, NVD, CISA, or FIRST.