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Fencer Vulns
critical 9.8

CVE-2021-35394 kev in the critical feed json

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.

published 2021-08-16 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-22037

cvss
9.8
version 3.1, CNA
cisa kev
Exploited
added 2021-12-10
epss
99.9%
EPSS 99.9% chance of exploitation in 30 days, percentile 99.9%
public exploits
0
none known, plus a Nuclei check

Summary

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.

Patch / fix

cisa required action Apply updates per vendor instructions.

Timeline

  1. Published
  2. Added to CISA KEV
  3. CISA patch deadline
  4. CISA SSVC: exploitation active

Known exploited

Added
4 y ago
Patch by
2021-12-24 (4 y ago)
Ransomware
Not known
Required action
Apply updates per vendor instructions.
Vendor, product
Realtek, Jungle Software Development Kit (SDK)
CISA name
Realtek Jungle SDK Remote Code Execution Vulnerability

ATT&CK techniques

How it is exploited and what it leads to, in MITRE ATT&CK terms.

  • T1190 Exploit Public-Facing Application exploitation
  • T1059 Command and Scripting Interpreter primary impact
  • T1071.001 Web Protocols secondary impact
  • T1105 Ingress Tool Transfer secondary impact
  • T1496 Resource Hijacking secondary impact
  • T1499 Endpoint Denial of Service secondary impact
  • T1569.002 Service Execution secondary impact

kev release 2025-07-28, att&ck v16.1. KEV to ATT&CK mappings by the MITRE Center for Threat-Informed Defense (Mappings Explorer, Apache-2.0). © 2026 The MITRE Corporation. This work is reproduced and distributed with the permission of The MITRE Corporation. Terms of use

CISA SSVC

Exploitation
Active, exploited in the wild
Automatable
yes
Technical impact
total
Assessed
21 mo ago

Exploit prediction

99.87% chance of exploitation in the next 30 days, higher than 99.9% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • Nuclei template RealTek AP Router SDK - Arbitrary Command Injection nuclei detection template
  • iot-inspector.com https://www.iot-inspector.com/blog/advisory-multiple-issues-realtek-sdk-iot-supply-chain referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CISA ADP 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CNA 3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 10.0 AV:N/AC:L/Au:N/C:C/I:C/A:C

Classification

Weakness
  • CWE-78 Improper Neutralization of Special Elements used in an OS Command

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.