CVE-2020-19201Network attack vector

Stored XSS via unencoded NAT rule descriptions

Published Jul 12, 2021 · Updated Aug 4, 2024

Stored XSS in the Netgate pfSense WebGUI 2.4.4-p2 and earlier allows remote authenticated users to execute JavaScript via a NAT rule. status_filter_reload.php inserts filter-reload output containing the NAT rule descr parameter into the page without output encoding. Viewing the filter-reload output triggers the stored payload, exposing session information or permitting actions within the victim's browser context.

CVSS severity5.4
Medium
EPSS probability3.45%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored XSS in the Netgate pfSense WebGUI 2.4.4-p2 and earlier allows remote authenticated users to execute JavaScript via a NAT rule. status_filter_reload.php inserts filter-reload output containing the NAT rule descr parameter into the page without output encoding. Viewing the filter-reload output triggers the stored payload, exposing session information or permitting actions within the victim's browser context.

The record

CVE
CVE-2020-19201
Published
Jul 12, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-79, T1539
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 12, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.4NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
3.5NIST NVDAV:N/AC:M/Au:S/C:N/I:P/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1539Steal Web Session Cookie

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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