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TapestryApplication · Apache

CVE-2020-17531

CRITICAL · 9.8 CVSS v3.1 Published 2020-12-08
Fix available
A fix is available. Upgrade to 5.0.1 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
A Java Serialization vulnerability was found in Apache Tapestry 4. Apache Tapestry 4 will attempt to deserialize the "sp" parameter even before invoking the page's validate method, leading to deserialization without authentication. Apache Tapestry 4 reached end of life in 2008 and no update to address this issue will be released. Apache Tapestry 5 versions are not vulnerable to this issue. Users of Apache Tapestry 4 should upgrade to the latest Apache Tapestry 5 version.

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

Apache Tapestry 4 contains a Java deserialization vulnerability where the 'sp' parameter is deserialized before authentication and before invoking the page's validate method, allowing unauthenticated attackers to inject malicious serialized objects leading to remote code execution.

MitigationUpgrade from Apache Tapestry 4 to the latest Apache Tapestry 5 version, as Tapestry 4 is end-of-life and no security patches will be released.

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
TapestryApplication
Affected:>= 4.0.0, < 5.0.1

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
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. Identify Tapestry version
    Locate Tapestry JAR files in the application's WEB-INF/lib directory, or inspect the application's pom.xml/build configuration. Look for JARs with names containing 'tapestry' and a version 4.x (such as tapestry-4.0.x.jar).
    Affected if Apache Tapestry version 4.0.0 through 4.0.19 (versions < 5.0.1) is found in the application deployment
  2. Confirm 'sp' parameter handling is active
    Review the application's Tapestry configuration files (typically in WEB-INF/ or the application root) for page serialization settings. The 'sp' parameter is used by Tapestry 4's page serialization/deserialization mechanism.
    Affected if The application has Tapestry 4 serialization configuration enabled, which allows the 'sp' parameter to trigger deserialization
  3. Check request handling for 'sp' parameter deserialization
    Examine the web.xml deployment descriptor and Tapestry filter configuration. Identify if the TapestryFilter processes requests before authentication is enforced.
    Affected if The TapestryFilter is mapped to process all requests (typically at '/*') and is not preceded by authentication filters in the filter chain
  4. Assess network exposure
    Determine if the affected Tapestry endpoints are accessible without authentication. Review URL access controls and network segmentation around the application.
    Affected if The application accepts unauthenticated HTTP requests that can include the 'sp' parameter, exposing the deserialization vulnerability to remote attackers

The environment is affected if Apache Tapestry 4 is deployed (version 4.0.0 to < 5.0.1), the page serialization feature using the 'sp' parameter is enabled, and the endpoints are reachable without authentication.

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 5.0.1 or later
Fixed in 5.0.1
Interim mitigation

Upgrade from Apache Tapestry 4 to the latest Apache Tapestry 5 version, as Tapestry 4 is end-of-life and no security patches will be released.

Recommended fix High confidence

Apache Tapestry 5 (latest stable version)

  1. Backup your current Apache Tapestry 4 application and configuration
  2. Download Apache Tapestry 5 from the official Apache Tapestry website (https://tapestry.apache.org/)
  3. Migrate your application code to be compatible with Apache Tapestry 5 APIs (Tapestry 5 has significant architectural differences from Tapestry 4)
  4. Update any project dependencies to use Tapestry 5 libraries
  5. Re-test your application functionality after the migration
  6. Deploy the migrated application
Caveat Tapestry 5 has significant architectural differences from Tapestry 4; substantial code changes will be required for migration

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

Fix this in Tapestry Scoped from the published advisory
  • Consultation30.0 h
  • Implementation150.0 h
  • Testing60.0 h
  • Review / QA30.0 h
270.0 hours of engineering $47,400
Get the upgrade done

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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-2020-17531 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
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  • Version or environment caveats, and links to real fixes
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