Known exploited · SonicWall
CVE-2020-5135: SonicWall SonicOS Buffer Overflow Vulnerability
What it is
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.
- Vendor
- SonicWall
- Product
- SonicOS
- Added to KEV
- March 15, 2022
- CISA due date
- April 5, 2022
- Ransomware use
- Known
What CISA requires
Apply updates per vendor instructions.
Forensic triage
No
What to do now
- Find every instance of SonicOS you run, including the forgotten ones, and check its version against the vendor advisory.
- Apply the vendor's fix or mitigation, before April 5, 2022 if you are bound by CISA's deadline, sooner if it faces the internet.
- Assume it was tried against you already: look for signs of exploitation from the date it was added, not from the day you patched.
References
H2 Security
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Start freeSource: CISA Known Exploited Vulnerabilities Catalog (public domain), catalog version 2026.10.01.