dbcve.org
ZentaoApplication · Easycorp

CVE-2020-28165

CRITICAL · 9.8 CVSS v3.1 Published 2021-08-12
Fix available
A fix is available. Upgrade to 12.4.2 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
The EasyCorp ZenTao PMS 12.4.2 application suffers from an arbitrary file upload vulnerability. An attacker can upload arbitrary webshell to the server by using the downloadZipPackage() function.

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

ZenTao PMS 12.4.2 contains an arbitrary file upload vulnerability in the downloadZipPackage() function. The function lacks proper validation on uploaded file types and content, allowing attackers to upload and execute malicious PHP webshells by bypassing file type restrictions.

MitigationUpdate to the vendor-patched version of ZenTao PMS. Until patched, disable or restrict access to the downloadZipPackage() function and implement strict allowlist-based file validation with content inspection on all upload endpoints.

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
ZentaoApplication
Affected:< 12.4.2

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

CVSS:3.1/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. Confirm ZenTao PMS is installed
    Check for ZenTao PMS files in the web root directory, typically found in /zentao, /pms, or similar paths. Look for the index.php entry point and the framework directory structure.
    Affected if ZenTao PMS software is present in the environment
  2. Identify the installed ZenTao version
    Locate the version file or header in the ZenTao installation. Common paths include version.php in the config directory or the header in the main index file. Compare the version number to the affected range of versions less than 12.4.2.
    Affected if The installed version is 12.4.2 or any version below 12.4.2
  3. Verify the downloadZipPackage function is accessible
    Check if the file upload functionality associated with downloadZipPackage is enabled. This typically involves checking if the module handling package downloads is loaded in the ZenTao module configuration.
    Affected if The downloadZipPackage functionality is accessible and enabled in the deployment
  4. Inspect file upload validation settings
    Review the upload validation logic in the ZenTao codebase, specifically looking at lib/mail/mail.class.php or similar upload handlers. Check if file type validation uses an allowlist approach and includes content inspection.
    Affected if File upload validation is missing, uses a simple extension check only, or lacks content-type inspection for uploaded files

You are affected if ZenTao PMS version 12.4.2 or lower is running with the downloadZipPackage function accessible and file upload validation does not include proper content-based allowlist checking.

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 12.4.2 or later
Fixed in 12.4.2
Interim mitigation

Update to the vendor-patched version of ZenTao PMS. Until patched, disable or restrict access to the downloadZipPackage() function and implement strict allowlist-based file validation with content inspection on all upload endpoints.

Recommended fix High confidence

12.4.2

  1. 1. Backup your current ZenTao installation and database before upgrading.
  2. 2. Download ZenTao version 12.4.2 or later from the official ZenTao website (www.zentao.net).
  3. 3. Follow the official upgrade documentation to apply the update to your existing installation.
  4. 4. Verify the upgrade was successful by logging into the ZenTao admin panel.
  5. 5. Confirm that the downloadZipPackage() function no longer accepts arbitrary file types by testing with a non-zip file.

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

Fix this in Zentao Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing3.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,490
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,984.

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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-2020-28165 in production — separate from our analysis above.

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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