CVE-2021-35394
Realtek Jungle SDK Remote Code Execution Vulnerability
Realtek Jungle Software Development Kit (SDK)
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.
Exploitation status
CISA Known Exploited Vulnerabilities
Listed by CISA on 10 December 2021. US federal agencies were required to remediate it by 24 December 2021.
EPSS — exploitation probability
FIRST puts the probability of exploitation activity in the next 30 days at 99.9%, which is higher than 99.9% of all scored vulnerabilities. EPSS is a forecast of activity, not a measure of severity, and it is rescored daily.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Frequently asked questions
Is CVE-2021-35394 being exploited by ransomware groups?
No ransomware group in this database is currently recorded as exploiting CVE-2021-35394.
What does CVE-2021-35394 affect?
CVE-2021-35394 affects Realtek Jungle Software Development Kit (SDK). 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.
How severe is CVE-2021-35394?
CVE-2021-35394 is rated CRITICAL with a CVSS base score of 9.8. EPSS puts the probability of exploitation in the next 30 days at 99.9%, higher than 99.9% of all scored vulnerabilities. It is listed in the CISA Known Exploited Vulnerabilities catalog, with a federal remediation deadline of 24 December 2021.
How should organisations respond to CVE-2021-35394?
Apply the vendor patch for Realtek Jungle Software Development Kit (SDK) as the first priority, and treat any internet-facing instance as the most urgent. Because this vulnerability is associated with ransomware activity, also review whether the affected systems were reachable before patching, rather than assuming that patching alone closes the incident.