Cyber Resilience

CVE-2021-20041

HighDDoS

Published: 08 December 2021

Published
08 December 2021
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0132 80.3th percentile
Risk Priority 16 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-20041 is a high-severity Infinite Loop (CWE-835) vulnerability in Sonicwall Sma 200 Firmware. Its CVSS base score is 7.5 (High).

Operationally, ranked in the top 19.7% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

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.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

sonicwall
sma 200 firmware
10.2.0.8-37sv, 10.2.1.1-19sv, 9.0.0.11-31sv
sonicwall
sma 210 firmware
10.2.0.8-37sv, 10.2.1.1-19sv, 9.0.0.11-31sv
sonicwall
sma 410 firmware
10.2.0.8-37sv, 10.2.1.1-19sv, 9.0.0.11-31sv
sonicwall
sma 400 firmware
10.2.0.8-37sv, 10.2.1.1-19sv, 9.0.0.11-31sv
sonicwall
sma 500v firmware
10.2.0.8-37sv, 10.2.1.1-19sv, 9.0.0.11-31sv

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-835

Enables transfer to alternate site if an infinite loop at the primary renders processing unavailable.

addresses: CWE-835

Detects and mitigates infinite loops that produce sustained resource consumption.

References