CVE-2021-20039
CVE-2021-20039 is a high-severity vulnerability in Sonicwall Sma 200 Firmware with a CVSS 3.x base score of 8.8. Its EPSS exploit-prediction score of 79% places it in the 100th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-78.
Key facts
- Severity: High (CVSS 3.x base score 8.8)
- CVSS v2: 9.0
- EPSS exploit prediction: 79% (100th percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-78
- Affected product: Sonicwall Sma 200 Firmware
- Published:
- Last modified:
Description
Improper neutralization of special elements in the SMA100 management interface '/cgi-bin/viewcert' POST http method allows a remote authenticated attacker to inject arbitrary commands as a 'nobody' user. This vulnerability affected SMA 200, 210, 400, 410 and 500v appliances.
Frequently asked questions
- What is CVE-2021-20039?
- Improper neutralization of special elements in the SMA100 management interface '/cgi-bin/viewcert' POST http method allows a remote authenticated attacker to inject arbitrary commands as a 'nobody' user. This vulnerability affected SMA 200, 210, 400, 410 and 500v appliances.
- How severe is CVE-2021-20039?
- CVE-2021-20039 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
- Is CVE-2021-20039 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 79% (100th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2021-20039?
- CVE-2021-20039 primarily affects Sonicwall Sma 200 Firmware. In total, 15 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
- How do I fix CVE-2021-20039?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- When was CVE-2021-20039 published?
- CVE-2021-20039 was published on 2021-12-08 and last updated on 2026-06-17.
References
- http://packetstormsecurity.com/files/165563/SonicWall-SMA-100-Series-Authenticated-Command-Injection.html
- https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0026
- https://attackerkb.com/topics/9szJhq46lw/cve-2021-20039/rapid7-analysis
Affected products (15)
- cpe:2.3:o:sonicwall:sma_200_firmware:9.0.0.11-31sv:*:*:*:*:*:*:*
- cpe:2.3:o:sonicwall:sma_200_firmware:10.2.0.8-37sv:*:*:*:*:*:*:*
- cpe:2.3:o:sonicwall:sma_200_firmware:10.2.1.1-19sv:*:*:*:*:*:*:*
- cpe:2.3:o:sonicwall:sma_210_firmware:9.0.0.11-31sv:*:*:*:*:*:*:*
- cpe:2.3:o:sonicwall:sma_210_firmware:10.2.0.8-37sv:*:*:*:*:*:*:*
- cpe:2.3:o:sonicwall:sma_210_firmware:10.2.1.1-19sv:*:*:*:*:*:*:*
- cpe:2.3:o:sonicwall:sma_410_firmware:9.0.0.11-31sv:*:*:*:*:*:*:*
- cpe:2.3:o:sonicwall:sma_410_firmware:10.2.0.8-37sv:*:*:*:*:*:*:*
- cpe:2.3:o:sonicwall:sma_410_firmware:10.2.1.1-19sv:*:*:*:*:*:*:*
- cpe:2.3:o:sonicwall:sma_400_firmware:9.0.0.11-31sv:*:*:*:*:*:*:*
- cpe:2.3:o:sonicwall:sma_400_firmware:10.2.0.8-37sv:*:*:*:*:*:*:*
- cpe:2.3:o:sonicwall:sma_400_firmware:10.2.1.1-19sv:*:*:*:*:*:*:*
- cpe:2.3:o:sonicwall:sma_500v_firmware:9.0.0.11-31sv:*:*:*:*:*:*:*
- cpe:2.3:o:sonicwall:sma_500v_firmware:10.2.0.8-37sv:*:*:*:*:*:*:*
- cpe:2.3:o:sonicwall:sma_500v_firmware:10.2.1.1-19sv:*:*:*:*:*:*:*
More vulnerabilities in Sonicwall Sma 200 Firmware
- CVE-2022-22273 — Critical (CVSS 9.8): Improper neutralization of Special Elements leading to OS Command Injection vulnerability impacting end-of-life Secure…
- CVE-2021-20045 — Critical (CVSS 9.8): A buffer overflow vulnerability in SMA100 sonicfiles RAC_COPY_TO (RacNumber 36) method allows a remote unauthenticated…
- CVE-2021-20042 — Critical (CVSS 9.8): An unauthenticated remote attacker can use SMA 100 as an unintended proxy or intermediary undetectable proxy to bypass…
- CVE-2021-20038 — Critical (CVSS 9.8): A Stack-based buffer overflow vulnerability in SMA100 Apache httpd server's mod_cgi module environment variables allows…
- CVE-2021-20016 — Critical (CVSS 9.8): A SQL-Injection vulnerability in the SonicWall SSLVPN SMA100 product allows a remote unauthenticated attacker to…
- CVE-2024-38475 — Critical (CVSS 9.1): Improper escaping of output in mod_rewrite in Apache HTTP Server 2.4.59 and earlier allows an attacker to map URLs to…
All CVEs affecting Sonicwall Sma 200 Firmware →
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