XSS in Smoothwall Express

CVE-2019-25378

Smoothwall Express 3.1-SP4-polar-x86_64-update9 contains multiple cross-site scripting vulnerabilities in the proxy.cgi endpoint that allow attackers to inject malicious scripts through parameters including CACHE_SIZE, MAX_SIZE, MIN_SIZE, MAX_OUTGOING_SIZE, and MAX_INCOMING_SIZE. Attackers can submit POST requests with script payloads to store or reflect arbitrary JavaScript code that executes in users' browsers when the proxy configuration page is accessed.

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.002 (13.3th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2019-25378?
CVE-2019-25378 is a medium-severity vulnerability in Smoothwall Express, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2026-02-16.
How severe is CVE-2019-25378?
Medium severity. CVSS v3 base score is 6.1 out of 10.