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

Vulnerability summary

CVE-2021-35394 is a high (CVSS 10.0) OS Command Injection vulnerability in Realtek Jungle Software Development Kit (SDK). It is known to be exploited: CISA and CIRCL list it, first on 10-12-2021. EPSS estimates a 99.88% chance of exploitation in the next 30 days, higher than 99.9% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 16-08-2021
   PublishedVulnerability first disclosed.
2. 10-12-2021
   Added to CISA KEVRealtek Jungle SDK Remote Code Execution Vulnerability
3. 24-12-2021
   CISA remediation dueApply updates per vendor instructions.
4. 21-10-2025
   Last modifiedVulnerability information updated.
5. 12-03-2026
   Added to CIRCL KEVAdded to the CIRCL known exploited vulnerabilities catalog.

Description

Realtek Jungle SDK version v2.x up to v3.4.14B provides a diagnostic tool called 'MP Daemon' that is usually compiled as 'UDPServer' binary. The binary is affected by multiple memory corruption vulnerabilities and an arbitrary command injection vulnerability that can be exploited by remote unauthenticated attackers.

• CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component.