Privilege escalation in Microsoft Windows
CVE-2021-20021
A vulnerability in the SonicWall Email Security version 10.0.9.x allows an attacker to create an administrative account by sending a crafted HTTP request to the remote host.
Vulnerability class: Privilege Escalation
EPSS: 0.834 (99.7th percentile) — read the EPSS interpretation.
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.
Affected products
- Microsoft Windows
- Sonicwall Email Security — versions 10.0.9 and earlier
- Sonicwall Email_security
- Sonicwall Email_security_appliance_3300
- Sonicwall Email_security_appliance_3300_firmware
- Sonicwall Email_security_appliance_4300
- Sonicwall Email_security_appliance_4300_firmware
- Sonicwall Email_security_appliance_5000
- Sonicwall Email_security_appliance_5000_firmware
- Sonicwall Email_security_appliance_5050
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@sonicwall.com (x_refsource_CONFIRM, Vendor Advisory)
- 134c704f-9b21-4f2e-91b3-4a467353bcc0 (US Government Resource)
Frequently asked questions
- What is CVE-2021-20021?
- CVE-2021-20021 is a critical-severity vulnerability in Microsoft Windows, classified under Improper Privilege Management. CVSS score: 9.8/10. Published 2021-04-09.
- How severe is CVE-2021-20021?
- Critical severity. CVSS v3 base score is 9.8 out of 10.
- Is CVE-2021-20021 known to be exploited?
- Yes. CVE-2021-20021 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2021-11-03), indicating it is being actively exploited. 5 public proof-of-concept repositories are indexed.