Cyber Resilience

CVE-2021-35393

Memory Safety in Realtek Rtl819X Jungle Software Development Kit 2.0 – 3.4.14b

Public PoCHigh EPSSMemory Safety
Published
16 August 2021
Modified
13 August 2025
Patch / advisory
CVSS Score v3.1 9.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.70 99.3th percentile
Risk Priority 96 floored blend · peak EPSS

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 0.7% 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 Data

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

Likely ATT&CK TechniquesAI

Techniques this vulnerability likely enables, inferred from its description, weakness type, and attributed-actor tradecraft. Confidence is per-technique.

T1190 Exploit Public-Facing Application Initial Accessconfidence: HIGH
The vulnerability is a remotely exploitable stack buffer overflow in a network-facing UPnP/SSDP service, directly enabling remote code execution via exploitation of a public-facing application.
T1068 Exploitation for Privilege Escalation Privilege Escalationconfidence: HIGH
Successful exploitation of the stack buffer overflow grants arbitrary code execution, which can be used to escalate privileges on the affected device.
inferred from description + CWE · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2023-50243Same product: Realtek Rtl819X Jungle Software Development Kit
CVE-2023-47856Same product: Realtek Rtl819X Jungle Software Development Kit
CVE-2023-50330Same product: Realtek Rtl819X Jungle Software Development Kit
CVE-2023-49867Same product: Realtek Rtl819X Jungle Software Development Kit
CVE-2023-45215Same product: Realtek Rtl819X Jungle Software Development Kit
CVE-2024-21778Same product: Realtek Rtl819X Jungle Software Development Kit
CVE-2023-49595Same product: Realtek Rtl819X Jungle Software Development Kit
CVE-2023-50239Same product: Realtek Rtl819X Jungle Software Development Kit
CVE-2023-41251Same product: Realtek Rtl819X Jungle Software Development Kit
CVE-2023-49073Same product: Realtek Rtl819X Jungle Software Development Kit

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.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure-development practices (static analysis, bounds checking, code review) are the primary means of preventing out-of-bounds writes.

ID.RA-01 partial match
prevents

Vulnerability scanning and recording can discover out-of-bounds write flaws so they can be remediated.

PR.PS-02 partial match
prevents

Patching or replacing vulnerable software directly eliminates known instances of this coding weakness.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

detects

Security testing in development and acceptance can detect and prevent out-of-bounds write defects.

prevents

Secure development life cycle mandates practices that prevent out-of-bounds writes.

prevents

Application security requirements can specify bounds-checking and safe memory handling.

prevents

Secure architecture and engineering principles reduce the likelihood of buffer overflows.

prevents

Secure coding directly addresses out-of-bounds writes through language choice and coding standards.

prevents

Change management can enforce review gates that catch unsafe memory operations before deployment.

References