CVE-2021-20038
SonicWall SMA 100 Appliances Stack-Based Buffer Overflow Vulnerability
Does this matter?
Known to be exploited in the wild (CISA KEV, CISA remediation deadline 11 February 2022). Treat as an emergency change: patch or isolate now, then hunt for prior compromise.
Description
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.
- CVSS 3.1
- 9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 99.91% probability · 100th percentile
- CISA KEV
- Listed 28 January 2022 · due 11 February 2022 · used in ransomware campaigns
- Weakness
- CWE-121, CWE-787
- Affected
- sonicwall/sma 200 firmware · sonicwall/sma 210 firmware · sonicwall/sma 410 firmware · sonicwall/sma 400 firmware · sonicwall/sma 500v firmware
- Source
- PSIRT@sonicwall.com
CISA notes
Apply updates per vendor instructions. https://nvd.nist.gov/vuln/detail/CVE-2021-20038
References
- https://github.com/jbaines-r7/badbloodExploit, Third Party Advisory
- https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0026Vendor Advisory
- https://www.rapid7.com/blog/post/2022/01/11/cve-2021-20038-42-sonicwall-sma-100-multiple-vulnerabilities-fixed-2/Exploit, Third Party Advisory
- https://github.com/jbaines-r7/badbloodExploit, Third Party Advisory
- https://psirt.global.sonicwall.com/vuln-detail/SNWLID-2021-0026Vendor Advisory
- https://www.rapid7.com/blog/post/2022/01/11/cve-2021-20038-42-sonicwall-sma-100-multiple-vulnerabilities-fixed-2/Exploit, Third Party Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-20038US Government Resource
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.