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Known exploited · Realtek

CVE-2021-35394: Realtek Jungle SDK Remote Code Execution Vulnerability

What it is

RealTek Jungle SDK contains multiple memory corruption vulnerabilities which can allow an attacker to perform remote code execution.

Added December 10, 2021Due December 24, 2021CISA KEV catalog 2026.10.01

Vendor
Realtek
Product
Jungle Software Development Kit (SDK)
Added to KEV
December 10, 2021
CISA due date
December 24, 2021
Ransomware use
Unknown

What CISA requires

Apply updates per vendor instructions.

Forensic triage

No

What to do now

  1. Find every instance of Jungle Software Development Kit (SDK) you run, including the forgotten ones, and check its version against the vendor advisory.
  2. Apply the vendor's fix or mitigation, before December 24, 2021 if you are bound by CISA's deadline, sooner if it faces the internet.
  3. Assume it was tried against you already: look for signs of exploitation from the date it was added, not from the day you patched.
  4. Until every instance is patched, block the attack at the edge: a WAF in blocking mode stops OS command injection payloads, including Shellshock.

References

CVE-2021-35394 in the National Vulnerability Database

The Dome

Block it at the edge while you patch

The Dome's WAF runs the OWASP Core Rule Set in blocking mode and stops OS command injection payloads, including Shellshock before they reach your application.

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Source: CISA Known Exploited Vulnerabilities Catalog (public domain), catalog version 2026.10.01.