SonicOS firewalls
CVE-2021-20031: Host Header Redirection in SonicOS
A Host Header Redirection vulnerability in SonicOS potentially allows a remote attacker to redirect firewall management users to arbitrary web domains.
Published
ExploitedNot in CISA KEV
Ransomware useNot reportedPer CISA
SeverityUnknown
EPSS13%Chance of exploitation in 30 days
Public exploitNot tracked
FixSee advisory
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 Host Header Redirection vulnerability in SonicOS potentially allows a remote attacker to redirect firewall management users to arbitrary web domains.
Sources
KEV status, EPSS score and vendor data refreshed automatically, last on 13 Oct 2026.