Security readout for executives and security teams
Plain-English summary
CVE-2018-21237 is a Foxit PhantomPDF issue in versions before 8.3.7 that can expose NTLM credentials through crafted PDF navigation actions. The business risk is credential capture, which can support follow-on access if password hashes or authentication material are abused.
Executive priority
Address in normal vulnerability remediation cycles, faster for teams that process external PDFs or operate in Windows domain environments. The issue can support credential theft, but the provided evidence does not show active exploitation or critical severity.
Technical view
The CVE describes NTLM credential theft in Foxit PhantomPDF before 8.3.7 via GoToE or GoToR actions. The source bundle provides no CVSS score, CWE, exploit details, or confirmed active exploitation. Treat this as a client-side document handling risk tied to legacy PhantomPDF deployments.
Likely exposure
Likely exposed systems are endpoints running Foxit PhantomPDF versions before 8.3.7, especially users who open PDFs from email, web downloads, or external partners. The provided sources do not identify other affected Foxit products.
Exploitation context
The source bundle says the issue enables NTLM credential theft through PDF actions. CISA KEV status is false, and no provided source confirms active exploitation. Evidence is limited to the CVE description and Foxit security bulletin reference.
Researcher notes
Key gaps are missing CVSS, CWE, detailed affected CPEs, and explicit exploit status. Analysis should stay limited to Foxit PhantomPDF before 8.3.7 and NTLM credential theft via GoToE or GoToR actions unless Foxit or CVE updates add scope.
Mitigation direction
- Inventory Foxit PhantomPDF installations and versions across managed endpoints.
- Upgrade PhantomPDF versions before 8.3.7 according to Foxit guidance.
- Review Foxit’s security bulletins for the exact fixed build and support status.
- Reduce exposure to untrusted PDFs until vulnerable clients are remediated.
- Monitor for suspicious outbound NTLM authentication from user workstations.
Validation and detection
- Confirm whether any endpoint runs Foxit PhantomPDF before 8.3.7.
- Check software inventory, EDR, or asset management records for PhantomPDF versions.
- Review recent endpoint logs for unexpected NTLM authentication attempts after PDF handling.
- Verify upgraded clients report version 8.3.7 or a later supported build.
- Document any compensating controls for systems that cannot be upgraded immediately.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
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.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
Credential and access behavior lookup
The CVE wording references authentication or credential exposure, so valid-account and credential-access review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2018-21237 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
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.
CVSS and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- https://www.foxitsoftware.com/support/security-bulletins.phpCVE reference · x_refsource_CONFIRM
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.