dbcve.org
Html\/java ApiApplication · Apache

CVE-2020-17534

HIGH · 7.0 CVSS v3.1 Published 2021-01-11
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
72/100
Remediation priority · Elevated
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
There exists a race condition between the deletion of the temporary file and the creation of the temporary directory in `webkit` subproject of HTML/Java API version 1.7. A similar vulnerability has recently been disclosed in other Java projects and the fix in HTML/Java API version 1.7.1 follows theirs: To avoid local privilege escalation version 1.7.1 creates the temporary directory atomically without dealing with the temporary file: https://github.com/apache/netbeans-html4j/commit/fa70e507e5555e1adb4f6518479fc408a7abd0e6

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

A time-of-check-time-of-use (TOCTOU) race condition exists in the webkit subproject of Apache NetBeans HTML4J (HTML/Java API) version 1.7 between the deletion of a temporary file and the creation of a temporary directory. An attacker with local access can exploit this race condition to achieve local privilege escalation by manipulating the temporary file/directory creation sequence.

MitigationUpgrade to HTML/Java API version 1.7.1 or later, which creates temporary directories atomically without relying on temporary file handling.

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
Html\/java ApiApplication
Affected:= 1.7

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
Local
Complexity
High
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:H/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 if Apache Html/Java API is present
    Locate any JAR files or library dependencies named html4j, netbeans-html4j, or html-java-api in your application or system. Check build files (pom.xml, build.gradle) for dependencies on Apache Html/Java API.
    Affected if The library is present in the environment
  2. Determine the installed version
    Inspect the version of the html4j dependency in your project's dependency management system or JAR manifest. For Maven projects, run 'mvn dependency:tree' or check pom.xml. For installed libraries, check the JAR filename or manifest for version 1.7.
    Affected if The version is exactly 1.7 (versions before 1.7 are not listed as affected, and 1.7.1+ has the fix)
  3. Verify the webkit component is in use
    Determine if your application or Apache NetBeans uses the webkit subproject of html4j. Check for imports or references to webkit-related classes, or examine which html4j modules are included in your deployment.
    Affected if The webkit component of html4j version 1.7 is being used
  4. Confirm temporary file operations occur
    The vulnerability manifests when the webkit component creates temporary files and directories during HTML rendering or web view initialization. Monitor or audit code paths that trigger webkit-based HTML rendering where temporary directories are created in system temp folders.
    Affected if Operations that trigger temporary file/directory creation by the webkit component are performed

You are affected if Apache Html/Java API version 1.7 with the webkit component is installed and operations that create temporary files/directories are performed by that component.

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
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade to HTML/Java API version 1.7.1 or later, which creates temporary directories atomically without relying on temporary file handling.

Fix this in Html\/java Api 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
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,088.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2020-17534 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

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-2020-17534 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

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