CVE-2021-20048
A Stack-based buffer overflow in the SonicOS SessionID HTTP response header allows a remote...
A Stack-based buffer overflow in the SonicOS SessionID HTTP response header allows a remote authenticated attacker to cause Denial of Service (DoS) and potentially results in code execution in the firewall. This vulnerability affected SonicOS Gen 5, Gen 6 and Gen 7 firmware versions.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
A Stack-based buffer overflow in the SonicOS SessionID HTTP response header allows a remote authenticated attacker to cause Denial of Service (DoS) and potentially results in code execution in the firewall. This vulnerability affected SonicOS Gen 5, Gen 6 and Gen 7 firmware versions.
- Record
CVE-2021-20048- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - CVSS 2.0
- 6.5 Medium
AV:N/AC:L/Au:S/C:P/I:P/A:P - Weakness
- CWE-121, CWE-787
- Updated
- 2026-11-09
CVE List No score
A Stack-based buffer overflow in the SonicOS SessionID HTTP response header allows a remote authenticated attacker to cause Denial of Service (DoS) and potentially results in code execution in the firewall. This vulnerability affected SonicOS Gen 5, Gen 6 and Gen 7 firmware versions.
- Record
CVE-2021-20048- Weakness
- CWE-121
- Updated
- 2026-11-02
EUVDEUVD-2021-7511 No score
A Stack-based buffer overflow in the SonicOS SessionID HTTP response header allows a remote authenticated attacker to cause Denial of Service (DoS) and potentially results in code execution in the firewall. This vulnerability affected SonicOS Gen 5, Gen 6 and Gen 7 firmware versions.
- Record
EUVD-2021-7511- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-248v-73qf-wh7x
A Stack-based buffer overflow in the SonicOS SessionID HTTP response header allows a remote...
A Stack-based buffer overflow in the SonicOS SessionID HTTP response header allows a remote authenticated attacker to cause Denial of Service (DoS) and potentially results in code execution in the firewall. This vulnerability affected SonicOS Gen 5, Gen 6 and Gen 7 firmware versions.
- Record
GHSA-248v-73qf-wh7x- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-121, CWE-787
- 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-2021-20048 is a high vulnerability (CVSS 8.8) in Sonicwall Sonicos, published January 7, 2022. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 2.00%, the 80th percentile. No source names a fixed version.