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Movable TypeApplication · Sixapart

CVE-2020-5577

HIGH · 8.8 CVSS v3.1 Published 2020-05-14
Fix available
A fix is available. Upgrade to after 7.2.1 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
Movable Type series (Movable Type 7 r.4606 (7.2.1) and earlier (Movable Type 7), Movable Type Advanced 7 r.4606 (7.2.1) and earlier (Movable Type Advanced 7), Movable Type for AWS 7 r.4606 (7.2.1) and earlier (Movable Type for AWS 7), Movable Type 6.5.3 and earlier (Movable Type 6.5), Movable Type Advanced 6.5.3 and earlier (Movable Type Advanced 6.5), Movable Type 6.3.11 and earlier (Movable Type 6.3), Movable Type Advanced 6.3.11 and earlier (Movable Type 6.3), Movable Type Premium 1.29 and earlier, and Movable Type Premium Advanced 1.29 and earlier) allow remote authenticated attackers to upload arbitrary files and execute a php script via unspecified vectors.

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

This is a file upload vulnerability in Movable Type CMS that allows authenticated remote attackers to upload arbitrary files, including PHP scripts, and execute them to achieve remote code execution. The vulnerability affects multiple versions across Movable Type 7, 6.5, 6.3, and Premium product lines.

MitigationUpgrade to Movable Type versions beyond r.4606 (7.2.1+), beyond 6.5.3 (6.5.4+), beyond 6.3.11 (6.3.12+), and beyond 1.29 (1.30+) as applicable. Alternatively, restrict file upload permissions and disable script execution in upload directories.

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
Movable TypeApplication
Affected:<= 1.29>= 6.3, <= 6.3.11>= 6.5.0, <= 6.5.3>= 7.0, <= 7.2.1

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 Movable Type installation
    Look for the mt-config.cgi configuration file in the web root or check for /mt/ admin paths. Search for directories named 'mt' or 'movable-type' that contain MT-specific files.
    Affected if Movable Type CMS is present on the server and accessible via web.
  2. Determine Movable Type version
    Open mt-config.cgi and look for the 'VersionID' or 'ApplicationVersion' setting. Alternatively, check for a VERSION file in the MT installation directory, or log into the admin interface and view the system information or about page.
    Affected if The installed version falls within any of these ranges: <= 1.29, >= 6.3 and <= 6.3.11, >= 6.5.0 and <= 6.5.3, or >= 7.0 and <= 7.2.1.
  3. Verify file upload capability is accessible
    Navigate to theMovable Type admin panel, then to the file upload settings or a blog's upload interface (typically under Tools > Files or Blog Settings > Files). Check if the upload functionality is enabled and accessible to user roles.
    Affected if File upload feature is enabled and the attacker can authenticate to access upload functionality.
  4. Inspect upload directory configuration
    In mt-config.cgi, locate the 'UploadDir' or 'StaticWebPath' directives to identify configured upload directories. Check these directories on the filesystem for permissions and contents.
    Affected if Upload directories exist and are web-accessible.
  5. Check upload directory script execution settings
    Examine the web server configuration (Apache .htaccess, nginx config) for the upload directories. Verify if directives like 'Options -ExecCGI' or 'php_flag engine off' are missing or if .php files are permitted to execute.
    Affected if Upload directories allow execution of uploaded files (e.g., PHP scripts) or no restrictions are in place to prevent script execution.

A user is affected if Movable Type is installed with a version in the vulnerable ranges AND file upload functionality is enabled AND upload directories permit script execution.

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 a release after 7.2.1
Interim mitigation

Upgrade to Movable Type versions beyond r.4606 (7.2.1+), beyond 6.5.3 (6.5.4+), beyond 6.3.11 (6.3.12+), and beyond 1.29 (1.30+) as applicable. Alternatively, restrict file upload permissions and disable script execution in upload directories.

Fix this in Movable Type Scoped from the published advisory
  • Consultation4.0 h
  • Implementation16.0 h
  • Testing8.0 h
  • Review / QA4.0 h
32.0 hours of engineering $5,600
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Scan for this in your stack

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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-2020-5577 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