Cyber Resilience

CVE-2021-35393

CriticalPublic PoC

Published: 16 August 2021

Published
16 August 2021
Modified
13 August 2025
KEV Added
Patch
CVSS Score v3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.1307 94.3th percentile
Risk Priority 27 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-35393 is a critical-severity Out-of-bounds Write (CWE-787) vulnerability in Realtek Rtl819X Jungle Software Development Kit. Its CVSS base score is 9.8 (Critical).

Operationally, ranked in the top 5.7% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability details

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…

more

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(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

realtek
rtl819x jungle software development kit
2.0 — 3.4.14b

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-787

Out-of-bounds writes that corrupt control flow or inject shellcode are rendered non-executable by the same memory protections.

References