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CVE Record

CVE-2021-39239: XML External Entity (XXE) vulnerability

A vulnerability in XML processing in Apache Jena, in versions up to 4.1.0, may allow an attacker to execute XML External Entities (XXE), including exposing the contents of local files to a remote server.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

Apache Jena versions up to 4.1.0 could process malicious XML in a way that lets an attacker trigger external entity handling. The stated impact is exposure of local file contents to a remote server. Business urgency depends on whether Jena parses attacker-controlled XML in your environment.

Executive priority

Treat this as a targeted remediation item for systems using Apache Jena with untrusted XML input. It is not documented as actively exploited here, but potential local file disclosure makes exposed deployments worth prioritizing.

Technical view

CVE-2021-39239 is an XML External Entity issue in Apache Jena XML processing. Sources state affected versions are up to 4.1.0 and the impact may include disclosure of local files via remote external entity resolution. No CVSS, CWE, or detailed exploit conditions are provided in the bundle.

Likely exposure

Organizations are most exposed where Apache Jena up to 4.1.0 processes untrusted XML or RDF/XML from users, partners, APIs, or automated feeds.

Exploitation context

The provided sources do not show CISA KEV listing or active exploitation. The risk is credible because XXE can leak local data when vulnerable XML parsers resolve attacker-controlled external entities.

Researcher notes

Evidence is limited to the CVE record and Apache mailing-list references. The bundle does not provide CVSS scoring, parser configuration details, proof-of-concept status, or complete patch mechanics. Avoid assuming exploitability without confirming XML input reachability.

Mitigation direction

  • Inventory Apache Jena versions and flag deployments at 4.1.0 or older.
  • Review Apache advisory guidance before choosing a target upgrade version.
  • Upgrade affected Jena components according to vendor guidance.
  • Restrict untrusted XML ingestion until affected components are remediated.
  • Monitor egress from Jena hosts for unexpected external callbacks.

Validation and detection

  • Check dependency manifests, SBOMs, and deployed artifacts for Apache Jena versions.
  • Identify code paths that parse XML or RDF/XML using Jena.
  • Confirm whether those paths accept external or user-controlled input.
  • Review logs for unusual outbound requests from Jena processing hosts.
  • Verify remediation by confirming no runtime uses Jena up to 4.1.0.
Prepared
Confidence
medium
Sources
6

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

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CVE-2021-39239 mapping review

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors
0Timeline events
0ADP providers
5Source links

CVSS and timeline data

No CVSS vectors or timeline events were available in the normalized CVE source material.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
Apache Software FoundationApache JenaunspecifiedListed
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.