Security readout for executives and security teams
Plain-English summary
A crafted PDF or page can make Foxit Reader 10.1.3.37598 write outside allocated memory and run attacker-controlled code as the user. The victim must open a malicious file or visit a malicious page. This is high-risk for endpoints that process untrusted PDFs.
Executive priority
Treat as high priority where Foxit Reader is deployed on user endpoints. The business risk is code execution from document handling, but exploitation requires user interaction and the provided evidence does not show known active exploitation.
Technical view
CVE-2021-31465 is a CWE-787 out-of-bounds write in Foxit Reader’s U3D object handling. Missing validation of user-supplied PDF data can write past an allocated data structure, enabling arbitrary code execution in the current process. The listed affected version is Foxit Reader 10.1.3.37598.
Likely exposure
Exposure is concentrated on workstations running Foxit Reader 10.1.3.37598, especially users who receive external PDFs or browse untrusted content. The supplied sources do not identify other affected Foxit products or versions.
Exploitation context
The source bundle says user interaction is required. The target must open a malicious file or visit a malicious page. CISA KEV is false in the bundle, and no cited source states active exploitation.
Researcher notes
ZDI tracks this as ZDI-21-554 and ZDI-CAN-13582. Note the CVSS vector is AV:L/UI:R while the narrative says remote attackers can trigger it through malicious pages or files. Do not expand affected scope beyond Foxit Reader 10.1.3.37598 from the bundle.
Mitigation direction
- Check Foxit’s security bulletin for fixed versions and vendor guidance.
- Update or replace Foxit Reader 10.1.3.37598 installations.
- Limit handling of untrusted PDFs until remediation is complete.
- Use endpoint and email controls to reduce malicious PDF exposure.
Validation and detection
- Inventory endpoints for Foxit Reader 10.1.3.37598.
- Compare installed versions against Foxit’s security bulletin.
- Review endpoint telemetry for suspicious Foxit Reader crashes or child processes.
- Confirm PDF filtering and attachment controls apply to high-risk users.
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.
CWE-787: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-31465 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
- High
- CVSS
- 7.8 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
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 vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H1.85.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
7.8HighVector: CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://www.foxitsoftware.com/support/security-bulletins.phpCVE reference · x_refsource_MISC
- https://www.zerodayinitiative.com/advisories/ZDI-21-554/CVE reference · x_refsource_MISC
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.
Out-of-bounds Write
Out-of-bounds Write represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.