CVE-2021-20041
An unauthenticated and remote adversary can consume all of the device's CPU due to crafted HTTP requests sent to SMA100 /fileshare/sonicfiles/sonicfiles resulting in a loop with unreachable exit condition.
Does this matter?
EPSS puts the probability of exploitation in the next 30 days at 21.2%, higher than 98% of all known CVEs. Patch or mitigate before the next change window.
Description
An unauthenticated and remote adversary can consume all of the device's CPU due to crafted HTTP requests sent to SMA100 /fileshare/sonicfiles/sonicfiles resulting in a loop with unreachable exit condition. This vulnerability affected SMA 200, 210, 400, 410 and 500v appliances.
- CVSS 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 21.20% probability · 98th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-835
- 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 21.2% on 2 October 2026 to 21.2% on 26 October 2026. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”.
References
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.