CVE-2021-20035
Published: April 16, 2025
Official Description
SonicWall SMA100 appliances contain an OS command injection vulnerability in the management interface that allows a remote authenticated attacker to inject arbitrary commands as a 'nobody' user, which could potentially lead to code execution.
CISA KEV Advisory
SonicWall SMA100 Appliances OS Command Injection Vulnerability
SonicWall SMA100 appliances contain an OS command injection vulnerability in the management interface that allows a remote authenticated attacker to inject arbitrary commands as a 'nobody' user, which could potentially lead to code execution.
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Risk Analysis
This OS command injection vulnerability in SonicWall SMA100 appliances' management interface allows a remote authenticated attacker to inject arbitrary commands, potentially leading to code execution. While a CVSS score is not available, its HIGH severity and inclusion in CISA's KEV catalog with an EPSS score of 0.03967 indicate a significant risk of exploitation.
This vulnerability is actively being exploited in the wild, as confirmed by its presence in CISA's KEV catalog. Exploitation is remote and requires authentication.
Update SonicWall SMA100 appliances to the latest patched firmware. Implement strong, unique passwords and multi-factor authentication for management interfaces, and restrict access to these interfaces.
Technical Analysis
CVE-2021-20035 requires local access, meaning attackers must already have a foothold on the target system.
Exploitation requires some privileges, which limits the exposure to scenarios where an attacker has already gained initial access.
CISA has added CVE-2021-20035 to the Known Exploited Vulnerabilities (KEV) catalog, confirming active exploitation in the wild. U.S. federal agencies are required to patch this within the mandated timeframe, and all organizations should treat remediation as urgent.
Exploit & PoC Resources
All References (2)
Quick Facts
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2021-20035 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts
- !CISA KEV: Federal agencies must patch per BOD 22-01 timeline
- !Active exploitation confirmed — treat as P1