CVE-2021-20035: SonicWall SMA100 Appliances OS Command Injection Vulnerability
Advisory generated from the CVE record, CISA, Exploit Observer and VEDAS: what it is, whether it is exploited, who is affected, and how to fix and detect it.
Generated by VEDAS. Scores as of 2026-11-01 19:19 UTC. Rebuilt every few hours from cve-scores, CISA KEV and vedas-signatures. How this works and its limits.
What it is
Improper neutralization of special elements in the SMA100 management interface allows a remote authenticated attacker to inject arbitrary commands as a ‘nobody’ user which potentially leads to DoS.
Description quoted from the CVE record (assigned by sonicwall, published 2021-09-27).
Weakness: CWE-78: Improper Neutralization of Special Elements used in an OS Command (‘OS Command Injection’)
How it can be exploited
Exploitable over the network with low attack complexity needing low privileges and no user interaction. Impact: confidentiality none, integrity none, availability high. CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CISA assessment (SSVC): CISA assesses exploitation as active. Automatable: no. Technical impact: total.
- On CISA KEV since
- 2025-04-16
- US federal deadline
- 2025-05-07
- Ransomware use
- Not known
Public exploit evidence (Exploit Observer)
Also known as: BDU:2025-05023, CNNVD-202109-1662, EUVD-2021-7498, GHSA-g24w-7v2m-52xh
Exploit Observer has no public exploit code that names this CVE or one of its aliases.
Research and write-ups (1)
- Research or write-up: https://www.rapid7.com/db/vulnerabilities/sonicwall-sma-100-cve-2021-20035
Vulnerability databases and vendor advisories (5)
Catalogue entries, not exploit evidence.
- Vulnerability database or vendor advisory: https://euvd.enisa.europa.eu/enisa/EUVD-2021-7498
- Vulnerability database or vendor advisory: https://github.com/advisories/GHSA-g24w-7v2m-52xh
- Vulnerability database or vendor advisory: https://nvd.nist.gov/vuln/detail/CVE-2021-20035
- Vulnerability database or vendor advisory: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-20035
- Vulnerability database or vendor advisory: https://www.cnnvd.org.cn/home/globalSearch?keyword=CNNVD-202109-1662
61 more references returned by Exploit Observer did not name this CVE or an alias, so they are left out.
VEDAS data as of 2026-11-01T17:12 UTC; fetched 2026-11-02.
Live scores
- EPSS
- 0.044
some chance of attack soon - VEDAS
- 0.696
some exploit evidence - On CISA KEV
- Yes, since 2025-04-16
- Detection rule
- None yet
Thin horizontal line: the “likely” (EPSS 0.10) or “strong” (VEDAS 0.90) threshold. Shaded “no data” areas are periods when cve-scores did not publish. The vertical line is the day CISA added it to its exploited list.
Who is affected
| Product | Affected | Not affected |
|---|---|---|
| SonicWall SMA100 | version 9.0.0.10-28sv and earlier version 10.2.0.7-34sv and earlier version 10.2.1.0-17sv and earlier | Not stated |
Version ranges exactly as the CVE record states them. “Before X” means X is the first fixed version.
Exploit Observer also maps it to: sonicwall sma_100, sonicwall sma_200, sonicwall sma_200_firmware, sonicwall sma_210, sonicwall sma_210_firmware, sonicwall sma_400, sonicwall sma_400_firmware, sonicwall sma_410, sonicwall sma_410_firmware, sonicwall sma_500v.
How to fix it
CISA required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Vendor guidance:
- https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0022
- https://nvd.nist.gov/vuln/detail/CVE-2021-20035
How to detect it
There is no open VEDAS detection rule for this bug yet. It is listed on the detection gaps page if CISA has confirmed attacks.
References
Government sources
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-20035 (government-resource)
Other references
- https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0022 (x_refsource_CONFIRM)
Other databases
Where this comes from
This advisory is generated automatically by VEDAS from: CVE.org record, CISA KEV, cve-scores (EPSS and VEDAS), Exploit Observer. Text in quotes is reproduced from the source; everything else is a fixed template filled with source fields. Nothing here is written by a language model. Check the vendor advisory before acting, and read how VEDAS and Exploit Observer work, and their limits.