CVE-2021-27912Network attack vector

Stored XSS via unescaped asset image title

Published Aug 30, 2021 · Updated Sep 16, 2024

Stored XSS in Acquia Mautic before 3.3.4 and 4.0.0 prereleases allows remote authenticated users to run JavaScript in asset viewers. AssetBundle/Views/Asset/preview.html.php inserted Asset::getTitle() unescaped into an image alt attribute, letting a broken image trigger an injected onerror handler. The attacker needs asset creation or editing permission, and execution occurs when another user views the crafted asset.

CVSS severity7.1
High
EPSS probability0.60%
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 Acquia Mautic before 3.3.4 and 4.0.0 prereleases allows remote authenticated users to run JavaScript in asset viewers. AssetBundle/Views/Asset/preview.html.php inserted Asset::getTitle() unescaped into an image alt attribute, letting a broken image trigger an injected onerror handler. The attacker needs asset creation or editing permission, and execution occurs when another user views the crafted asset.

The record

CVE
CVE-2021-27912
Published
Aug 30, 2021
Updated
Sep 16, 2024
Vendor
Acquia
Product
Mautic
Classifications
CWE-79, T1203
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 30, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=unspecified <3.3.4
  2. Affected versionversion=unspecified <4.0.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Acquia · Mauticversion=unspecified <3.3.4; version=unspecified <4.0.0

Published CVSS scores

7.1MauticCVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H
5.4NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
3.5NVDAV: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')
T1203Exploitation for Client Execution

Public exploit references

No public exploit references are available in this record.

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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