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Contao CmsApplication · Contao

CVE-2017-16558

CRITICAL · 9.8 CVSS v3.0 Published 2019-04-25
Fix available
A fix is available. Upgrade to after 4.4.7 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges 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
Contao 3.0.0 to 3.5.30 and 4.0.0 to 4.4.7 contains an SQL injection vulnerability in the back end as well as in the listing module.

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

SQL injection vulnerability in Contao CMS affecting versions 3.0.0 through 3.5.30 and 4.0.0 through 4.4.7, present in both the back end administrative interface and the listing module. The critical severity (CVSS 9.8) indicates easy exploitation with potential for complete database compromise.

MitigationUpgrade Contao to version 3.5.31 or later, or 4.4.8 or later to patch the SQL injection vulnerability. If immediate upgrading is not possible, restrict backend access to trusted users only as a temporary measure.

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
Contao CmsApplication
Affected:>= 3.0.0, <= 3.5.30>= 4.0.0, <= 4.4.7

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
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.0/AV:N/AC:L/PR:N/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 Contao installation and version
    Locate the Contao installation directory. Check for a version file or system information page. Common locations include the root directory or a system/info endpoint. Compare the found version against the affected ranges: 3.0.0 to 3.5.30, or 4.0.0 to 4.4.7.
    Affected if The installed Contao version falls within the 3.0.0-3.5.30 or 4.0.0-4.4.7 range.
  2. Determine if backend administrative interface is accessible
    Attempt to access the Contao back end login page. Common paths include /contao or /admin. Verify the login page loads successfully.
    Affected if The Contao back end is accessible on the network and the version is within the affected range.
  3. Check if listing module is enabled
    Examine the Contao configuration or module settings to determine if the listing module is installed and active. This may be found in the module configuration files or through the back end module manager.
    Affected if The listing module is enabled and the Contao version is within the affected range.
  4. Verify database user privileges
    Review the database configuration file (typically system/config/localconfig.php or similar) to identify the database user credentials used by Contao. Assess whether the application database user has excessive privileges beyond what is required.
    Affected if The database user has privileges that could allow an attacker to read, modify, or delete database contents if the SQL injection is exploited.

A user is affected if their Contao installation version is between 3.0.0 and 3.5.30, or between 4.0.0 and 4.4.7, and either the back end or listing module is accessible.

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.

dbcve · scoped
Upgrade available Upgrade to a release after 4.4.7
Interim mitigation

Upgrade Contao to version 3.5.31 or later, or 4.4.8 or later to patch the SQL injection vulnerability. If immediate upgrading is not possible, restrict backend access to trusted users only as a temporary measure.

Recommended fix High confidence

Contao 4.4.8 or later (or latest Contao 4.x/5.x); Contao 3.5.31 if still on 3.x branch

  1. 1. Backup your Contao installation and database before proceeding
  2. 2. For Contao 4.x installations: Upgrade to Contao 4.4.8 or later (recommended: latest 4.4 LTS or migrate to Contao 4.9+/4.13+)
  3. 3. For Contao 3.x installations: Upgrade to Contao 3.5.31 or later (note: Contao 3 is end-of-life; migrate to Contao 4.x recommended)
  4. 4. Run the Contao install tool to update the database schema if needed
  5. 5. Clear all caches after upgrade
  6. 6. Verify the back end and listing modules function correctly
  7. 7. Test that SQL injection is no longer exploitable
Caveat Contao 3.x is end-of-life; upgrade to Contao 4.x may require theme/template adjustments and PHP version compatibility checks

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Contao Cms Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing4.0 h
  • Review / QA2.0 h
15.0 hours of engineering $2,640
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,224.

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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-2017-16558 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