Is CVE-2021-35393 in the CISA KEV catalog?

No. CVE-2021-35393 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2021-35393?

CVE-2021-35393 has a CVSS v3 base score of 9.8 (CRITICAL).

What is the EPSS score for CVE-2021-35393?

CVE-2021-35393 has an EPSS score of 70.33% (99th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix or mitigate CVE-2021-35393?

No published fix for CVE-2021-35393 has been found yet. Check the linked vendor advisories for guidance as it becomes available.

CVE & CISA-KEV Catalog

CVE-2021-35393

CRITICALEPSS 99th pctl

9.8

CVSS v3

NVD

Description

Realtek Jungle SDK version v2.x up to v3.4.14B provides a 'WiFi Simple Config' server that implements both UPnP and SSDP protocols. The binary is usually named wscd or mini_upnpd and is the successor to miniigd. The server is vulnerable to a stack buffer overflow vulnerability that is present due to unsafe parsing of the UPnP SUBSCRIBE/UNSUBSCRIBE Callback header. Successful exploitation of this vulnerability allows remote unauthenticated attackers to gain arbitrary code execution on the affected device.

CWE-787Out-of-bounds Write

How to fix

No published remediation has been found for this vulnerability's affected products yet.

Mitigation guidance may be in the linked vendor advisories in the References section below.

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CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

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

Exploit Intelligence

70.33%probability of exploitation in 30 days

99thpercentile

Very high risk: more likely to be exploited than 99% of all known CVEs.

References

Patch2

Exploit1

iot-inspector.com

Related Vulnerabilities

Other CWE-787 (Out-of-bounds Write) vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2025-22457	Critical	9.0	100%	KEV + Ransom	Fix
CVE-2025-0282	Critical	9.0	100%	KEV + Ransom	-
CVE-2015-3113	Critical	9.8	100%	KEV	Fix
CVE-2021-20038	Critical	9.8	100%	KEV + Ransom	-
CVE-2023-4863	High	8.8	100%	KEV	Fix
CVE-2020-16040	Medium	6.5	100%	-	Fix

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2025-08-13.