9.8
Critical
CVE-2020-5135 SonicWall SonicOS Buffer Overflow Vulnerability
Active exploitation observed
· CISA KEV catalogue
Required action
Apply updates per vendor instructions.
Ransomware campaigns
Known to be used
Weakness
CWE-120
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.
Affected products and versions
| Product | Affected versions | Fixed in |
|---|---|---|
| SonicOS | Versions not published |
Other CVEs of SonicOS
The 75 CVEs of SonicOS →
CVE-2026-19703
A weak password hashing vulnerability has been identified on SonicOS virtual appliances, which in specific conditions…
5.1
Medium
CVE-2026-77709
A pre-authentication heap-based buffer overflow vulnerability has been identified in the SonicOS TACACS+…
5.9
Medium
CVE-2026-77708
A pre-authentication stack-based buffer overflow vulnerability has been identified in the SonicOS TACACS+ authentication…
5.9
Medium
CVE-2026-19868
SonicWall SonicOS SSLVPN Use of Single-factor Authentication Vulnerability
7.5
High