Security readout for executives and security teams
Plain-English summary
CVE-2021-31450 is a high-severity Foxit Reader flaw that can let an attacker run code when a user opens a malicious file or visits a malicious page. The business risk is endpoint compromise through document handling, not unauthenticated server takeover.
Executive priority
Prioritize remediation where Foxit Reader is deployed broadly or used with external documents. Treat this as endpoint compromise risk requiring timely patch validation.
Technical view
The flaw affects Foxit Reader 10.1.1.37576 in XFA form handling. The reported issue is a use-after-free/object existence validation failure that can allow code execution in the current process. CVSS is 7.8 with user interaction required.
Likely exposure
Exposure is likely limited to endpoints running Foxit Reader 10.1.1.37576, especially where users handle external PDFs or web-delivered document content.
Exploitation context
The provided sources require user interaction: opening a malicious file or visiting a malicious page. The bundle does not show CISA KEV listing or confirmed active exploitation.
Researcher notes
ZDI tracks this as ZDI-21-539 and ZDI-CAN-13084. The CVE maps to CWE-416. Evidence names Foxit Reader 10.1.1.37576 only; do not expand affected versions without vendor confirmation.
Mitigation direction
- Inventory endpoints running Foxit Reader 10.1.1.37576.
- Apply Foxit security guidance or update to a vendor-supported fixed release.
- Restrict or inspect untrusted PDF handling until affected clients are remediated.
- Educate users to avoid unexpected PDF attachments and links.
Validation and detection
- Confirm installed Foxit Reader versions across managed endpoints.
- Check whether Foxit security updates addressing this advisory are installed.
- Review endpoint telemetry for suspicious Foxit Reader child processes or crashes.
- Validate email and web controls inspect or block risky PDF delivery paths.
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-416: 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-2021-31450 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-21-539/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.
Use After Free
Use After Free represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.