CVE-2021-20027
A buffer overflow vulnerability in SonicOS allows a remote attacker to cause a Denial of Service ...
A buffer overflow vulnerability in SonicOS allows a remote attacker to cause a Denial of Service (DoS) by sending a specially crafted request. This vulnerability affects SonicOS Gen5, Gen6, Gen7 platforms, and SonicOSv virtual firewalls.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
A buffer overflow vulnerability in SonicOS allows a remote attacker to cause a Denial of Service (DoS) by sending a specially crafted request. This vulnerability affects SonicOS Gen5, Gen6, Gen7 platforms, and SonicOSv virtual firewalls.
- Record
CVE-2021-20027- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - CVSS 2.0
- 5.0 Medium
AV:N/AC:L/Au:N/C:N/I:N/A:P - Weakness
- CWE-120
- Updated
- 2026-11-09
CVE List No score
A buffer overflow vulnerability in SonicOS allows a remote attacker to cause a Denial of Service (DoS) by sending a specially crafted request. This vulnerability affects SonicOS Gen5, Gen6, Gen7 platforms, and SonicOSv virtual firewalls.
- Record
CVE-2021-20027- Weakness
- CWE-120
- Updated
- 2026-11-02
EUVDEUVD-2021-7490 No score
A buffer overflow vulnerability in SonicOS allows a remote attacker to cause a Denial of Service (DoS) by sending a specially crafted request. This vulnerability affects SonicOS Gen5, Gen6, Gen7 platforms, and SonicOSv virtual firewalls.
- Record
EUVD-2021-7490- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-j2f2-fj3p-8c94
A buffer overflow vulnerability in SonicOS allows a remote attacker to cause a Denial of Service ...
A buffer overflow vulnerability in SonicOS allows a remote attacker to cause a Denial of Service (DoS) by sending a specially crafted request. This vulnerability affects SonicOS Gen5, Gen6, Gen7 platforms, and SonicOSv virtual firewalls.
- Record
GHSA-j2f2-fj3p-8c94- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-120
- Updated
- 2026-11-09
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| facts | GitHub Advisories | |
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-20027 is a high vulnerability (CVSS 7.5) in Sonicwall Sonicos, published June 14, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.29%, the 70th percentile. No source names a fixed version.