Buffer overflow in SonicWall Sma 200
CVE-2021-20038
A Stack-based buffer overflow vulnerability in SMA100 Apache httpd server's mod_cgi module environment variables allows a remote unauthenticated attacker to potentially execute code as a 'nobody' user in the appliance. This vulnerability affected SMA 200, 210, 400, 410 and 500v appliances firmware 10.2.0.8-37sv, 10.2.1.1-19sv, 10.2.1.2-24sv and earlier versions.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.999 (100.0th percentile), scored .
Very high probability of exploitation in the next 30 days — among the top 0.1% most-likely-to-be-exploited CVEs. 100th percentile — 100.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.999 · newest: 0.999 · change: 0.000
Affected products
- SonicWall Sma 200
- SonicWall Sma 200 Firmware — versions 10.2.0.8-37sv, 10.2.1.1-19sv, 10.2.1.2-24sv
- SonicWall Sma 210
- SonicWall Sma 210 Firmware — versions 10.2.0.8-37sv, 10.2.1.1-19sv, 10.2.1.2-24sv
- SonicWall Sma 400
- SonicWall Sma 400 Firmware — versions 10.2.0.8-37sv, 10.2.1.1-19sv, 10.2.1.2-24sv
- SonicWall Sma 410
- SonicWall Sma 410 Firmware — versions 10.2.0.8-37sv, 10.2.1.1-19sv, 10.2.1.2-24sv
- SonicWall Sma 500v
- SonicWall Sma 500v Firmware — versions 10.2.0.8-37sv, 10.2.1.1-19sv, 10.2.1.2-24sv
Weakness classification (CWE)
CISA KEV (Known Exploited Vulnerabilities)
This CVE is on the CISA KEV catalog, added on . CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.
BOD 22-01 due date: .
Required action: Apply updates per vendor instructions.
Known ransomware campaign use: yes.
Public proof-of-concept exploits
References
- psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0026 (Vendor Advisory)
- github.com/jbaines-r7/badblood (Exploit, Third Party Advisory)
- www.rapid7.com/blog/post/2022/01/11/cve-2021-20038-42-sonicwall-sma-100-multipl… (Exploit, Third Party Advisory)
- 134c704f-9b21-4f2e-91b3-4a467353bcc0 (US Government Resource)
Frequently asked questions
- What is CVE-2021-20038?
- CVE-2021-20038 is a critical-severity vulnerability in SonicWall Sma 200, classified under Stack-based Buffer Overflow. CVSS score: 9.8/10. Published 2021-12-08.
- How severe is CVE-2021-20038?
- Critical severity. CVSS v3 base score is 9.8 out of 10.
- Is CVE-2021-20038 known to be exploited?
- Yes. CVE-2021-20038 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2022-01-28), indicating it is being actively exploited. 29 public proof-of-concept repositories are indexed.