SonicOS firewalls
CVE-2021-20048: A Stack-based buffer overflow in the SonicOS SessionID HTTP response header allows a remote authenticated a…
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.
Published
Automatic summary from the vendor's CVE record. We haven't written a full analysis of this vulnerability yet.
Affected and fixed versions
| Product / branch | Fixed in |
|---|---|
| SonicOS 7.0 | See the advisory |
| SonicOS 6.5 | See the advisory |
| SonicOS 6.0 | See the advisory |
| SonicOS 5.9 | See the advisory |
Always confirm against the vendor advisory, which lists every fixed hotfix.
What it is
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.
Sources
KEV status, EPSS score and vendor data refreshed automatically, last on 13 Oct 2026.