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
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: 0.888 (99.8th percentile), scored .
High probability of exploitation in the next 30 days — patch promptly. 100th percentile — 99.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.834 · newest: 0.888 · change: +0.054
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.global.sonicwall.com/vuln-detail/SNWLID-2021-0007 (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.