CVE-2021-35393 in the critical feed json
Realtek Jungle SDK version v2.x up to v3.4.14B provides a 'WiFi Simple Config' server that implements both UPnP and SSDP protocols.
published 2021-08-16 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-22036
- cvss
- 9.8
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 66.4%
- EPSS 66.4% chance of exploitation in 30 days, percentile 99.2%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
Exploit prediction
66.39% chance of exploitation in the next 30 days, higher than 99.2% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- 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 |
|---|---|---|---|
| NVD | 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-787 Out-of-bounds Write
References
-
realtek.com
/en/cu-1-en/cu-1-taiwan-en
broken-link, patch, vendor-advisory
-
realtek.com
/images/safe-report/Realtek_APRouter_SDK_Advisory-CVE-2021-35392_35395.pdf
patch, vendor-advisory
-
iot-inspector.com
/blog/advisory-multiple-issues-realtek-sdk-iot-supply-chain
broken-link, exploit, third-party-advisory
Sources
- CVE List CVE-2021-35393
- NVD CVE-2021-35393
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.