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TYPO3CMS

CVE-2019-19849

HIGH · 8.8 CVSS v3.1 Published 2019-12-17
Fix available
A fix is available. Upgrade to 8.7.30 / 9.5.12 or later.
See remediation →
94/100
Remediation priority · Urgent
Remotely reachable Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
An issue was discovered in TYPO3 before 8.7.30, 9.x before 9.5.12, and 10.x before 10.2.2. It has been discovered that the classes QueryGenerator and QueryView are vulnerable to insecure deserialization. One exploitable scenario requires having the system extension ext:lowlevel (Backend Module: DB Check) installed, with a valid backend user who has administrator privileges. The other exploitable scenario requires having the system extension ext:sys_action installed, with a valid backend user who has limited privileges.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

TYPO3 before versions 8.7.30, 9.5.12, and 10.2.2 contains insecure deserialization vulnerabilities in the QueryGenerator and QueryView classes. Exploitation requires either the ext:lowlevel system extension with an administrator backend user, or ext:sys_action with a limited-privilege backend user. The high CVSS score (8.8) reflects the ability to achieve code execution through deserialization gadget chains.

MitigationUpgrade to TYPO3 8.7.30, 9.5.12, 10.2.2 or later. If upgrading is not immediately feasible, disable or remove the ext:lowlevel and ext:sys_action system extensions if not required, and ensure backend user privileges follow least-privilege principles.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
TYPO3CMS
Affected:< 8.7.30>= 9.0.0, < 9.5.12>= 10.0.0, < 10.2.2

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify installed TYPO3 version
    Locate the TYPO3 version via the backend admin panel (Help > About) or check the composer.json file, or the TYPO3 version file in the installation root
    Affected if The installed version falls within < 8.7.30, or >= 9.0.0 and < 9.5.12, or >= 10.0.0 and < 10.2.2
  2. Verify ext:lowlevel system extension status
    Check the Extension Manager or typo3conf/pac/extensions directory to determine if the lowlevel system extension is installed and enabled
    Affected if The ext:lowlevel extension is installed and enabled on the system
  3. Verify ext:sys_action system extension status
    Check the Extension Manager or typo3conf/pac/extensions directory to determine if the sys_action system extension is installed and enabled
    Affected if The ext:sys_action extension is installed and enabled on the system
  4. Assess backend user privileges
    Review backend user accounts in the admin panel under User Management to identify users with administrator privileges and users with access to QueryGenerator or QueryView functionality
    Affected if An administrator backend user exists while ext:lowlevel is enabled, or any backend user exists while ext:sys_action is enabled

The environment is affected if the TYPO3 version is in the vulnerable range AND either ext:lowlevel is enabled with an administrator backend user OR ext:sys_action is enabled with any backend user present.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Upgrade available Upgrade to 8.7.30 / 9.5.12 / 10.2.2 or later
Fixed in 8.7.309.5.1210.2.2
Interim mitigation

Upgrade to TYPO3 8.7.30, 9.5.12, 10.2.2 or later. If upgrading is not immediately feasible, disable or remove the ext:lowlevel and ext:sys_action system extensions if not required, and ensure backend user privileges follow least-privilege principles.

Fix this in TYPO3 Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,930
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2019-19849 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data