CVE-2021-4226

CRITICAL 9.8CVE-2021-4226 · Published 15/12/2022 · updated 17/06/2026

In short

CVE-2021-4226 is a CRITICAL (CVSS 9.8) vulnerability affecting rsfirewall! (rsjoomla).
Chance of exploitation in the next 30 days (EPSS): 0.55%, higher than 45.8% of all vulnerabilities.
Fix: update to 1.1.25 or later.

Package	Affected versions	Patched versions
rsfirewall! rsjoomla	`< 1.1.25`	`1.1.25`

RSFirewall tries to identify the original IP address by looking at different HTTP headers. A bypass is possible due to the way it is implemented.

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