How severe is CVE-2021-35394?

CVE-2021-35394 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-35394 being actively exploited?

Yes. CVE-2021-35394 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2021-12-10, which means active exploitation has been confirmed. It should be prioritised for remediation.

What products are affected by CVE-2021-35394?

CVE-2021-35394 affects Realtek Rtl819x Jungle Software Development Kit. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-35394?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Because this CVE is known to be actively exploited, treat remediation as urgent — CISA KEV typically sets a short remediation deadline.

Does CVE-2021-35394 have an EU (EUVD) identifier?

Yes. CVE-2021-35394 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-22037. It is also flagged as exploited in the EUVD (since 2021-12-10).

When was CVE-2021-35394 published?

CVE-2021-35394 was published on 2021-08-16 and last updated on 2026-06-17.

CVE-2021-35394

CVE-2021-35394 is a critical-severity vulnerability in Realtek Rtl819x Jungle Software Development Kit with a CVSS 3.x base score of 9.8. It is listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, confirming it has been exploited in the wild (added 2021-12-10). The underlying weakness is classified as CWE-78.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 10.0
EPSS exploit prediction: 100% (100th percentile)
Actively exploited: Yes — listed in CISA KEV (added 2021-12-10)
EU (EUVD) id: EUVD-2021-22037
EU exploitation: Flagged exploited in the ENISA EU Vulnerability Database (since 2021-12-10)
Weakness: CWE-78
Affected product: Realtek Rtl819x Jungle Software Development Kit
Published: 2021-08-16
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2021-35394?: 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.
How severe is CVE-2021-35394?: CVE-2021-35394 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-35394 being actively exploited?: Yes. CVE-2021-35394 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2021-12-10, which means active exploitation has been confirmed. It should be prioritised for remediation.
What products are affected by CVE-2021-35394?: CVE-2021-35394 affects Realtek Rtl819x Jungle Software Development Kit. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-35394?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Because this CVE is known to be actively exploited, treat remediation as urgent — CISA KEV typically sets a short remediation deadline.
Does CVE-2021-35394 have an EU (EUVD) identifier?: Yes. CVE-2021-35394 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-22037. It is also flagged as exploited in the EUVD (since 2021-12-10).
When was CVE-2021-35394 published?: CVE-2021-35394 was published on 2021-08-16 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:realtek:rtl819x_jungle_software_development_kit:*:*:*:*:*:*:*:*

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