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CVE Record

CVE-2018-20239: Application Links before version 5.0.11, from version 5.1.0 before 5.2.10, from version 5.3.0 before 5.3.6,...

Application Links before version 5.0.11, from version 5.1.0 before 5.2.10, from version 5.3.0 before 5.3.6, from version 5.4.0 before 5.4.12, and from version 6.0.0 before 6.0.4 allows remote attackers to inject arbitrary HTML or JavaScript via a cross site scripting (XSS) vulnerability in the applinkStartingUrl parameter. The product is used as a plugin in various Atlassian products where the following are affected: Confluence before version 6.15.2, Crucible before version 4.7.0, Crowd before version 3.4.3, Fisheye before version 4.7.0, Jira before version 7.13.3 and 8.x before 8.1.0.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2018-20239 is a cross-site scripting flaw in Atlassian Application Links. A remote attacker could inject HTML or JavaScript through the applinkStartingUrl parameter. Because Application Links is used inside several Atlassian server products, affected collaboration and development systems should be prioritized for version review and upgrade.

Executive priority

Treat this as a targeted remediation item for legacy Atlassian environments. It is not KEV-listed in the supplied bundle, but XSS in collaboration platforms can affect trusted user sessions and internal workflows. Confirm exposure and patch during the next appropriate maintenance window, sooner for public systems.

Technical view

The vulnerable component is Atlassian Application Links before 5.0.11, 5.1.0 before 5.2.10, 5.3.0 before 5.3.6, 5.4.0 before 5.4.12, and 6.0.0 before 6.0.4. The issue is XSS in applinkStartingUrl and affects listed Confluence, Crucible, Crowd, Fisheye, and Jira versions.

Likely exposure

Exposure is most likely where older Atlassian Server deployments use bundled or installed Application Links. The source bundle names Confluence before 6.15.2, Crucible before 4.7.0, Crowd before 3.4.3, Fisheye before 4.7.0, Jira before 7.13.3, and Jira 8.x before 8.1.0.

Exploitation context

The provided sources describe remote HTML or JavaScript injection, but do not cite active exploitation, public exploit activity, authentication requirements, or CVSS scoring. CISA KEV is false in the bundle, so active exploitation should not be assumed from this evidence alone.

Researcher notes

Evidence is limited to the CVE description and Atlassian tracker references. No CVSS vector, CWE, exploit maturity, or detailed attack prerequisites are provided. The clearest validation path is version-based exposure analysis across the named Atlassian products and Application Links version ranges.

Mitigation direction

  • Upgrade affected Atlassian products to the fixed versions listed in the CVE record or later.
  • Confirm the Application Links component is at a fixed version or vendor-supported replacement.
  • Review Atlassian issue links for product-specific fix notes and deployment guidance.
  • Prioritize internet-facing or broadly accessible Atlassian instances first.
  • If upgrade timing is constrained, check Atlassian guidance for supported temporary mitigations.

Validation and detection

  • Inventory Confluence, Crucible, Crowd, Fisheye, Jira, and Application Links versions.
  • Compare installed versions against the affected ranges in the CVE description.
  • Check whether exposed Atlassian instances are reachable by untrusted users.
  • Review logs for unusual requests referencing applinkStartingUrl, without replaying them.
  • Verify post-upgrade that product and plugin versions meet the fixed thresholds.
Prepared
Confidence
medium
Sources
8

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-2018-20239 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
7Source 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
AtlassianAtlassian Application Linksunspecified, 5.1.0, unspecified, 5.3.0, unspecified, 5.4.0, unspecified, 6.0.0, unspecifiedListed
Weakness

CWE details

No CWE listed

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