CVE-2021-20035
SonicWall SMA100 Appliances OS Command Injection Vulnerability
SonicWall SMA100 Appliances
Improper neutralization of special elements in the SMA100 management interface allows a remote authenticated attacker to inject arbitrary commands as a 'nobody' user which potentially leads to DoS.
Exploitation status
CISA Known Exploited Vulnerabilities
Listed by CISA on 16 April 2025. US federal agencies were required to remediate it by 7 May 2025.
EPSS — exploitation probability
FIRST puts the probability of exploitation activity in the next 30 days at 4.4%, which is higher than 91.4% 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:L/UI:N/S:U/C:N/I:N/A:H
Frequently asked questions
Is CVE-2021-20035 being exploited by ransomware groups?
No ransomware group in this database is currently recorded as exploiting CVE-2021-20035.
What does CVE-2021-20035 affect?
CVE-2021-20035 affects SonicWall SMA100 Appliances. Improper neutralization of special elements in the SMA100 management interface allows a remote authenticated attacker to inject arbitrary commands as a 'nobody' user which potentially leads to DoS.
How severe is CVE-2021-20035?
CVE-2021-20035 is rated MEDIUM with a CVSS base score of 6.5. EPSS puts the probability of exploitation in the next 30 days at 4.4%, higher than 91.4% of all scored vulnerabilities. It is listed in the CISA Known Exploited Vulnerabilities catalog, with a federal remediation deadline of 7 May 2025.
How should organisations respond to CVE-2021-20035?
Apply the vendor patch for SonicWall SMA100 Appliances 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.