CVE-2020-5135
SonicWall SonicOS Buffer Overflow Vulnerability
- Critical 9.8
- Exploited: added to CISA KEV 15 Mar 2022
- Used in ransomware campaigns
Description
A buffer overflow vulnerability in SonicOS allows a remote attacker to cause Denial of Service (DoS) and potentially execute arbitrary code by sending a malicious request to the firewall. This vulnerability affected SonicOS Gen 6 version 6.5.4.7, 6.5.1.12, 6.0.5.3, SonicOSv 6.5.4.v and Gen 7 version 7.0.0.0.
Key facts
- Published
- 12 Oct 2020
- Last changed
- 21 Oct 2025
- Assigned by
- sonicwall
- KEV added
- 15 Mar 2022
- KEV fix due
- 5 Apr 2022
- Used in ransomware
- Yes, according to CISA
- EPSS
- 26.869% likely to be exploited in the next 30 days, higher than 98.065% of CVEs (scores for 15 Nov 2026)
- SSVC (CISA)
- Exploitation: active; Automatable: yes; Technical impact: total
Severity scores
Each score is shown as its source gave it. They are not averaged or merged.
- 9.8CVSS 3.1, Criticalfrom CISA (ADP container)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
What to do
- Apply updates per vendor instructions.CISA KEV required action
Historical context and remediation
This reference retains the original CVE publication date. A recent record update does not mean a new attack occurred.
No separately sourced impact summary is available on this page yet. Consult the description, version data and dated exploitation evidence.
Version statuses below come from the CNA. An “unaffected” version is not necessarily a currently supported release or proof of a patch date. EPSS is a dated risk estimate, not a count of historical attacks.
Affected products
| Vendor | Product | Versions |
|---|---|---|
| SonicWall | SonicOS |
|
Timeline
- 12 Oct 2020 Published
- 15 Mar 2022 CVE-2020-5135 added to CISA KEV
- 15 Mar 2022 Added to the CISA KEV catalogue