Security readout for executives and security teams
Plain-English summary
CVE-2021-31459 is a 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 workstation compromise through document handling, not an unauthenticated internet-facing server breach.
Executive priority
Treat this as a high-priority endpoint remediation issue where Foxit Reader is used to handle external documents. It requires user interaction, but successful exploitation could compromise the user’s workstation with the user’s process privileges.
Technical view
The flaw affects Foxit Reader 10.1.1.37576 in XFA Forms handling. Sources describe missing validation of an object before operations, mapped to CWE-416, allowing code execution in the current process after user interaction. CVSS is 7.8 high with confidentiality, integrity, and availability impact.
Likely exposure
Exposure is likely limited to endpoints running Foxit Reader 10.1.1.37576, especially systems that open externally supplied PDF or web content. The provided sources do not indicate affected servers, cloud services, or other Foxit products.
Exploitation context
User interaction is required: the target must open a malicious file or visit a malicious page. The source bundle does not show CISA KEV listing or other evidence of active exploitation, so exploitation should not be described as confirmed in the wild.
Researcher notes
ZDI identified the issue as ZDI-CAN-13162 and describes the vulnerable area as XFA Forms. Evidence is sufficient for affected version, impact, and interaction requirement, but the source bundle does not provide a fixed version, exploit availability, or active exploitation evidence.
Mitigation direction
- Inventory Foxit Reader deployments and identify version 10.1.1.37576.
- Review Foxit security bulletins for the fixed Reader release and remediation guidance.
- Prioritize remediation on users handling external PDFs or untrusted web content.
- Use email and web controls to reduce delivery of untrusted PDF content.
- Consider temporary removal where immediate remediation is not feasible.
Validation and detection
- Confirm whether Foxit Reader 10.1.1.37576 is installed on managed endpoints.
- Check whether Foxit Reader is the default PDF handler for high-risk users.
- Verify remediated systems are no longer on the affected build.
- Review security tooling for suspicious Foxit Reader child processes or crashes.
- Document any exceptions with owner, exposure rationale, and remediation date.
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-2021-31459 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-21-548/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.