VulnerabilityModified
CVE-2021-20042
An unauthenticated remote attacker can use SMA 100 as an unintended proxy or intermediary undetectable proxy to bypass firewall rules.
CRITICAL 9.8EPSS 3.68%
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (3.68%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
An unauthenticated remote attacker can use SMA 100 as an unintended proxy or intermediary undetectable proxy to bypass firewall rules. This vulnerability affected SMA 200, 210, 400, 410 and 500v appliances.
- CVSS 3.1
- 9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 3.68% probability · 90th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-441
- Affected
- sonicwall/sma 200 firmware · sonicwall/sma 210 firmware · sonicwall/sma 410 firmware · sonicwall/sma 400 firmware · sonicwall/sma 500v firmware
- Source
- PSIRT@sonicwall.com
EPSS moved from 3.7% on 2 October 2026 to 3.7% on 26 October 2026.
References
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.