Cyber Resilience

CVE-2021-20034

CriticalPublic PoC

Published: 27 September 2021

Published
27 September 2021
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 9.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
EPSS Score 0.0544 90.4th percentile
Risk Priority 21 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-20034 is a critical-severity Improper Access Control (CWE-284) vulnerability in Sonicwall Sma 200 Firmware. Its CVSS base score is 9.1 (Critical).

Operationally, ranked in the top 9.6% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability details

An improper access control vulnerability in SMA100 allows a remote unauthenticated attacker to bypass the path traversal checks and delete an arbitrary file potentially resulting in a reboot to factory default settings.

CWE(s)

Related Threats

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

Affected Assets

sonicwall
sma 200 firmware
≤ 9.0.0.10-28sv · 10.2.0.0 — 10.2.0.7-34sv · 10.2.1.0 — 10.2.1.0-17sv
sonicwall
sma 210 firmware
≤ 9.0.0.10-28sv · 10.2.0.0 — 10.2.0.7-34sv · 10.2.1.0 — 10.2.1.0-17sv
sonicwall
sma 400 firmware
≤ 9.0.0.10-28sv · 10.2.0.0 — 10.2.0.7-34sv · 10.2.1.0 — 10.2.1.0-17sv
sonicwall
sma 410 firmware
≤ 9.0.0.10-28sv · 10.2.0.0 — 10.2.0.7-34sv · 10.2.1.0 — 10.2.1.0-17sv
sonicwall
sma 500v
≤ 9.0.0.10-28sv · 10.2.0.0 — 10.2.0.7-34sv · 10.2.1.0 — 10.2.1.0-17sv

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-284

The access control policy and procedures directly mandate and enforce proper access control mechanisms across the organization.

addresses: CWE-284

Device lock enforces restricted access until re-authentication, directly reducing unauthorized use of active sessions.

addresses: CWE-284

Supervision and review of access control activities directly detects and remediates improper access configurations or usages.

addresses: CWE-284

Explicitly identifying and documenting actions permitted without identification or authentication enforces proper access control boundaries by defining justified exceptions.

addresses: CWE-284

By automatically labeling outputs with security attributes, the control supports attribute-based enforcement and reduces exploitability of improper access control weaknesses.

addresses: CWE-284

Associating and retaining security attributes with data directly supports enforcement of access control decisions across storage, processing, and transmission.

addresses: CWE-284

Requiring prior authorization for each remote access type prevents improper access control over remote connections.

addresses: CWE-284

Requiring authorization of wireless access before allowing connections enforces proper access control for this access method.

References