Security readout for executives and security teams
Plain-English summary
Foxit Reader 10.1.4.37651 can mishandle document objects so a malicious file or page could run code as the logged-in user. It requires the victim to open content or visit a malicious page, so this is primarily a phishing and document-delivery risk, not a wormable internet exposure.
Executive priority
Treat as high priority for workstation patching, especially in user populations exposed to external documents. It requires user action, but the impact is full endpoint compromise in the user context if triggered.
Technical view
CVE-2021-34831 is a high-severity Foxit Reader flaw in Document object handling. The source describes missing validation that an object exists before operations are performed on it, mapped to CWE-416. CVSS is 7.8 with user interaction required and high confidentiality, integrity, and availability impact.
Likely exposure
Exposure is limited to endpoints running Foxit Reader 10.1.4.37651. Risk is higher where users routinely receive external PDFs, browse untrusted sites, or lack application isolation and endpoint controls.
Exploitation context
The bundle does not show CISA KEV listing or active exploitation. Exploitation requires user interaction: opening a malicious file or visiting a malicious page. Successful exploitation runs code in the current process context.
Researcher notes
Evidence is constrained to the CVE description, Foxit bulletin reference, and ZDI advisory reference. The bundle names the affected version and vulnerability class but does not provide exploit details, active exploitation evidence, or a specific patched version.
Mitigation direction
- Identify and prioritize hosts running Foxit Reader 10.1.4.37651.
- Check Foxit security bulletins for the vendor-approved fixed version or mitigation.
- Update or remove affected Foxit Reader installations following vendor guidance.
- Limit opening external PDFs on affected endpoints until remediated.
- Use endpoint controls to reduce impact from document-borne code execution.
Validation and detection
- Inventory installed Foxit Reader versions across managed endpoints.
- Confirm no systems remain on version 10.1.4.37651.
- Verify remediation against Foxit’s published security bulletin.
- Review email and web controls for untrusted document delivery.
- Document exceptions with compensating controls and owner approval.
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-2021-34831 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.foxit.com/support/security-bulletins.htmlCVE reference · x_refsource_MISC
- https://www.zerodayinitiative.com/advisories/ZDI-21-913/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.