CVE-2019-16512Public exploitNetwork attack vector

Visitor browser code execution via stored appearance HTML

Published Jan 23, 2020 · Updated Aug 5, 2024

Stored XSS in ConnectWise Control 19.3.25270.7185 allows remote authenticated users to execute JavaScript in visitors' browsers. The Appearance modifier stores arbitrary HTML in LoginPanel.LoginReason.None.Message and renders it on the unauthenticated login page without neutralizing executable markup. Control administrator access is required to save the payload, and a victim must visit the login page; the script then runs in the Control origin.

CVSS severity4.8
Medium
EPSS probability1.22%
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 ConnectWise Control 19.3.25270.7185 allows remote authenticated users to execute JavaScript in visitors' browsers. The Appearance modifier stores arbitrary HTML in LoginPanel.LoginReason.None.Message and renders it on the unauthenticated login page without neutralizing executable markup. Control administrator access is required to save the payload, and a victim must visit the login page; the script then runs in the Control origin.

The record

CVE
CVE-2019-16512
Published
Jan 23, 2020
Updated
Aug 5, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-79, T1189
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Jan 23, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 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 privilegesadmin

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

3.5NIST NVDAV:N/AC:M/Au:S/C:N/I:P/A:N
4.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/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.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesadmin
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1189Drive-by Compromise

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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